US20060249671A1 - Method and device for non-contact sampling and detection - Google Patents
Method and device for non-contact sampling and detection Download PDFInfo
- Publication number
- US20060249671A1 US20060249671A1 US11/122,459 US12245905A US2006249671A1 US 20060249671 A1 US20060249671 A1 US 20060249671A1 US 12245905 A US12245905 A US 12245905A US 2006249671 A1 US2006249671 A1 US 2006249671A1
- Authority
- US
- United States
- Prior art keywords
- gas
- ions
- ion
- analyte
- reactant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J49/00—Particle spectrometers or separator tubes
- H01J49/02—Details
- H01J49/10—Ion sources; Ion guns
- H01J49/14—Ion sources; Ion guns using particle bombardment, e.g. ionisation chambers
- H01J49/145—Ion sources; Ion guns using particle bombardment, e.g. ionisation chambers using chemical ionisation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode
- G01N27/622—Ion mobility spectrometry
- G01N27/624—Differential mobility spectrometry [DMS]; Field asymmetric-waveform ion mobility spectrometry [FAIMS]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J49/00—Particle spectrometers or separator tubes
- H01J49/02—Details
- H01J49/10—Ion sources; Ion guns
- H01J49/14—Ion sources; Ion guns using particle bombardment, e.g. ionisation chambers
- H01J49/142—Ion sources; Ion guns using particle bombardment, e.g. ionisation chambers using a solid target which is not previously vapourised
Definitions
- This invention relates to a method and apparatus for the direct, non-contact, real-time sampling and detection of minute quantities of materials on surfaces.
- this invention relates to a method and apparatus for producing ions from targeted sample molecules on or above a surface that is spaced apart from the apparatus and for detecting and identifying those ions, all without contacting the surface.
- the present invention provides a complete means to scan surfaces such as paper, plastics, skin, glass and textiles from variable distances and determine in seconds if targeted chemicals or materials are present, completely independent of the vapor pressures of such chemicals.
- Currently available detectors generally create ions of the vapors of targeted chemicals and other chemicals taken into the body of the detector, then separate the ions and detect, identify and provide notification of the presence of any targeted chemicals.
- the present invention overcomes this limitation by creating ions from sample chemicals exterior to the detector, on surfaces, and draws these ions into the detector for separation, detection, identification and notification.
- reactant ions are created within the detector from a constant supply of conditioned air or other gas. These reactant ions are focused and accelerated as they leave the detector.
- the reactant ion stream impacts the chemicals on a surface exterior to the detector and creates surface sample chemical ions. These ions are drawn into another part of the detector, using electronic means to control ion movement and collection.
- the surface sample chemical ions are separated from the ambient air in which they are collected, and simultaneously moved and concentrated in a stream of constant composition air. The ions are then detected and identified after movement into a micro differential mobility spectrometer having no moving parts and made much like an integrated circuit.
- ion mobility spectrometers require an ion source, which may be a radioactive ionization source ( ⁇ -emitter or electron producer) such as 63 Ni.
- a radioactive ionization source such as 63 Ni.
- alternative ionization sources such as corona discharge ionization sources are preferred.
- corona discharge is described in U.S. Pat. No. 6,225,623. Corona discharge units have been and are widely used with helium gas to produce long-lived metastable helium atoms.
- the source comprises a chamber having an inlet port and an outlet port for passage of a carrier gas, and a pair of electrodes arranged to create a corona discharge within the chamber.
- the carrier gas helium or nitrogen
- the carrier gas is passed through the corona discharge causing formation of, among other species, neutral, excited state, metastable species of the carrier gas.
- Those excited state carrier gas molecules upon leaving the device then contact the sample, or analyte, and by transfer of energy from the excited state carrier gas molecules to analyte molecules, produce analyte ions.
- the analyte ions in the carrier gas are then passed to a charged particle or ion sensor, which may be the sensing element of a mass spectrometer or an ion mobility spectrometer.
- a charged particle or ion sensor which may be the sensing element of a mass spectrometer or an ion mobility spectrometer.
- the helium metastable atoms leave the confines of the device and subsequently react with surface materials to produce surface sample ions.
- the neutral helium metastable and energetic atoms are then reacted with the chemical components of air or other gases such as dopants, introduced within the device, causing the formation of reactant ions, such as O 2 ⁇ and H 3 O + , and electrons within the device.
- reactant ions such as O 2 ⁇ and H 3 O +
- reactant ions such as O 2 ⁇ and H 3 O +
- neutral metastable helium atoms can interact with other metastable atoms and with neutral ground state atoms to produce charged species. So, even if ion filters are used at this stage, ions can still be produced.
- the advantage of using filters is that they remove the ions produced during passage of the gas through the corona discharge.
- these reactant ions are positively or negatively charged and can be focused and accelerated within the device, and after they leave the device, they can be moved towards or away from different parts of the device depending upon the potential applied to that part of the device. Furthermore, these reactant ions can react with most chemicals to produce ions from those chemicals. The electrons produced can also react with gases to produce reactant ions.
- automated distance information from a rangefinder can provide feedback control to the ion focusing and accelerating portions of the invention.
- the reactant ions created within the invention can be focused on a surface such that the same amount of ions per unit area hit the surface independent of the distance between the detector and the surface. This allows the operator freedom of movement of the detector away from and towards the surface with assurance that, regardless of position, the same amount of detector initiated reactant ions will generate the same amount of sample ions on the surface, and ultimately, the same sensor-driven signal within the detector.
- the reactant ions created within the invention are those well known to react with a wide variety of chemicals of interest, to form predominantly molecular ions. Molecular fragmentation is kept to a minimum in this “soft” ionization process. This greatly simplifies the detection and identification process.
- the reactant ions emitted from the detector can be confined within a sheath gas such that, in the transit between detector and surface, the integrity of the detector originated ion population is largely maintained and admixing with the ambient air between the detector and the surface sample is kept to a minimum.
- IMS ion mobility spectrometry
- the first, or reaction, region contains the ionization source and is separated from the drift region by an electrical shutter or ion gate.
- the sample molecules are directly subjected to the ionization source and, depending upon the sample and the intensity of the source, a wide variety of molecular fragments, as well as simple ions, are produced.
- the mixture of reactant and product ions reaches an ion gate that separates the reaction region and the drift region.
- the ions With a bias voltage applied, the ions are attracted to the ion gate and lose their charge. Then the bias is briefly turned off, and ions are transmitted into the drift region of the cell.
- DMS differential mobility spectrometry
- MicroDMx manufactured by Sionex Corporation. This device has no moving parts and is microfabricated. Its small size allows for extremely fast clear down times and very rapid responses to the presence of ions.
- selectivity is significantly enhanced relative to other techniques of ion resolution and detection.
- DMS exploits the way in which the mobility of ions changes in response to changes in an applied variable high electric field, and this provides substantially more information relating to a molecule's identity than other methods, consequently leading to a significant reduction in false positives.
- Differential mobility spectrometry can detect positive and negative ions simultaneously and has superior sensitivity and selectivity capabilities relative to more commonly used sensors such as ion mobility spectrometers.
- DMS achieves superior selectivity relative to simple time-of-flight information employed in other detectors by using placement of ions within four-dimensional space constructed to examine changes in ion mobility as a function of changes in high electric field strength. Detection and identification are rapidly made and notification of presence or absence of targeted materials given in near-real time. Sensitivity is enhanced as well because as a range of compensation voltages in a DMS device are scanned the actual percentage of ions detected for any type of ion species is significantly higher (>10 ⁇ ) than in conventional IMS.
- DMS digital tomography
- sensitivity of DMS is higher than that of conventional IMS, and DMS sensors have the capability to detect compounds in the parts per trillion ranges.
- Differential mobility spectrometry can be used to detect positive and negative ions simultaneously. This is important in cases where all surface sample ions created would be collected at the same time, or where positive and negative ions would be alternately collected for extremely short times. These attributes of DMS are very important for the detection of explosives or other dangerous or controlled materials on clothing, baggage, paper, etc. at security checkpoints.
- DMS selectivity of DMS for certain materials such as explosives can be enhanced by transferring ions from an incoming ambient air stream to an air stream of controlled composition, possibly containing a dopant chemical to further control the nature of the ion species in the stream.
- the ion collection device undergoes programmed biasing aimed at providing sufficient charge opposite to that of the produced surface sample ions, thereby “pulling” these ions toward the collection device and into the sensor for detection and identification.
- the maximum possible number of collected ions must reach the sensor to attain the highest sensitivity.
- the ions are focused such that they are transported without touching the walls.
- reactant ions of one charge could form both positively and negatively charged surface sample ions. In this case, for each “burst” of reactant ions released on the surface sample, there would be two cycles of ion collection—one positive and one negative.
- the continuous detection of residual or unreacted reactant ions by the differential mobility spectrometer provides a means for feedback and other control of the detection system.
- feedback can be used, in conjunction with the distance from the detector reactant ion production device to the surface (provided by a rangefinder) to control the timing of changes of potential applied to the ion collection inlet, relative to those changes of potential controlling the production of reactant ions, as the distance between the detector and surface is changed. This has the practical effect of providing assurance that relatively the same number of ions is detected by the detector as it is moved toward or away from the surface.
- the operator does not have to keep the detector at a fixed distance from the targeted surface and allows for freedom of movement of the detector toward or away from the surface with assurance that targeted surface materials will still be detected with relatively the same certainty.
- feedback control without using the rangefinder but using the DMS signal, can be used to control the density of reactant ions projected from the ion production means, thereby controlling the overall sensitivity of the detector.
- a means to generate ions of targeted chemicals on surfaces coupled with a small fast sensor with excellent sensitivity and selectivity, and the means to use distance and sensor information as feedback to control the entire process provides the elements of a detector that can be used to close security loopholes. It will enable the rapid screening of the surfaces of people, baggage, cargo, parcels and vehicles at government and private facilities, transportation centers, checkpoints and borders, among others. It will also find use in substantiating illegal activities by facilitating the rapid and accurate detection of chemical warfare agents (CWAs), explosives and illicit substances and to verify decontamination efforts are successful by military personnel.
- CWAs chemical warfare agents
- Key features of the invention are means to control, focus and accelerate the detector originated reactant ions responsible for producing surface sample ions from chemicals on surfaces, and the coordination of these events with the rapid collection of the surface originated ions in high yields for detection and identification by the sensor.
- the capability to apply roughly the same amount of reactant ions to the same surface area regardless of the distance of the detector from the surface allows the operator to scan the surface from variable detector—surface distances and obtain the same result, rather than be constrained to holding the detector at a fixed, close distance from the surface.
- an ion production and sensor system that operates by impacting a reactant ion stream upon a surface to form ions of sample compounds carried on that surface, to collect at least some of the sample ions that are formed, and to pass those ions into, for example, a differential mobility spectrometer to identify and quantify the sample compounds.
- Another object of this invention is to provide an extremely sensitive, fully portable, hand-held detector that can identify and quantify compounds such as drugs and chemical warfare agents in place on surfaces without physical contact of those surfaces.
- Yet another object of this invention is to detect equally well the presence of sample compounds having extremely low or hugely different vapor pressures without physical contact of the surface that carries the sample compounds.
- the detector system of this invention includes two major parts.
- First is a reactant ion production device having the capability to produce reactant ions from introduced air or other gases, and to filter, focus and accelerate such reactant ions constrained within a sheath gas or not as appropriate, toward a surface, generating surface sample ions from the chemicals on that surface.
- Second is an ion collection device that collects surface sample ions produced by the interaction of reactant ions with sample chemicals on the surface.
- the ion collection device has the capability to transfer such sample ions from the ambient air in which they are collected to a controlled air stream, to introduce reactant gases or dopants that can modify the structure, charge and/or adduct formation or dissociation of the sample ions, and to introduce the ions into a differential mobility spectrometer. Events in the ion production and ion collection devices are fully coordinated to maximize sample ion production and collection. Feedback controls, using information from a rangefinder and the spectrometer or sensor, enable similar ion detection results to be obtained regardless of the distance between the detector and the surface.
- FIG. 1 is a schematic representation showing the arrangement of the reactant ion production and surface sample ion collection, detection and identification means according to this invention
- FIG. 2 is a schematic representation of a first reactant ion production means of the FIG. 1 system
- FIG. 3 is a schematic representation of another embodiment of the reactant ion production means of FIG. 2 ;
- FIG. 4 is another embodiment of the reactant ion production means of FIGS. 2 and 3 , including a means for concentrating ions and changing the ion carrier gas as is illustrated in FIG. 8 ;
- FIG. 5 is a cross sectional view of the ion production means of FIG. 4 taken along line 5 - 5 ′;
- FIG. 6 is a diagrammatic representation of a surface sample ion detection and identification means according to the present invention.
- FIG. 7 is a partial, cross sectional representation of the surface sample ion detection and identification means of FIG. 6 ;
- FIG. 8 is a cross-sectional representation of an ion inlet arranged with a surface sample ion concentration and change of ion carrier gas means for use with the detection and identification means of FIGS. 6 and 7 ;
- FIGS. 9 a through 9 d depict the first half of a cycle of the production of ions, showing the production of negatively charged reactant ions, creation of negatively charged surface sample ions and collection of such surface sample ions using the reactant ion production means of FIGS. 2, 3 and 4 , and the surface sample collection, detection and identification means of FIGS. 7 and 8 when operated in a pulsed mode;
- FIGS. 10 a through 10 d depict the second half of a cycle of the production of ions, showing the production of positively charged reactant ions, creation of positively charged surface sample ions and collection of such surface sample ions using the reactant ion production means of FIGS. 2 3 and 4 , and the surface sample collection, detection and identification means of FIGS. 7 and 8 when operated in a pulsed mode;
- FIG. 11 is a generally schematic diagram of the arrangement of components in an operating system for a detector according to the teachings of this invention.
- this invention can be viewed as a method and means for conducting a three-step energy transfer process that may then be followed by an analytical procedure.
- Energy is applied to a first gas by means of a corona discharge, forming ions and other energetic species of that gas.
- the energetic species of the first gas then transfer energy to a second gas, which must have at least one component with an ionization potential, or ionization energy, less than that of the energetic species of the first gas so as to produce reactant ions of the second gas.
- Those reactant ions are caused to impact upon a surface, reacting with chemicals or other materials on the surface to produce analyte ions that are collected, detected and identified.
- a significant advantage of this downhill energy flow is that it utilizes energy from an inexpensive, relatively uncontrolled high energy source (corona discharge) and converts it into energetic species that provide a “soft” ionization of analytes. That is, the reaction of Gas 2 reactant ions with analytes produces mainly molecular ions rather than ionized structural fragments. This simplifies the detection and identification process in a wide variety of situations.
- Selectivity can be achieved by changing the gas from air to other gases having different ionization potentials, such as ammonia, 10.2 e.V.; acetone, 9.7 e.V.; or di n-propylamine, 7.8 e.V.
- Reactant ions from each of these gases would ionize organic chemicals having ionization potentials less than that of the respective gas. This provides for selectivity based on ionization potential.
- the gas ions or neutral species can combine with the surface analyte ions to produce ion/molecular clusters that can aid in analyte ion identification and separation.
- Electronic potentials at different places are used to manipulate the types and populations of reactant ions formed and issued from the reactant ion production device and of the types and populations of surface sample ions collected by the surface sample ion collection device. Also, real-time distance of detector to surface information, and detector sensor information provide automatic feedback control of these potentials. This feedback control manages and maximizes the instantaneous active interplay between the detector and the surface sample under investigation. On one hand, the reactant ion density put on the surface sample is maintained relatively constant and independent of working distance between the detector and the surface sample. On the other, the collection efficiency of the surface sample ion collector is optimized and collected ion loss prior to entry into the sensor is minimized. These events are automatically managed and coordinated such that operator input to the process is not necessary.
- the detector system 10 of FIG. 1 operates at ambient pressure, without sample contact, by producing a stream 12 of either ions or a mixture of ions and metastable excited state molecules, in ion production means 14 .
- Stream 12 is then directed toward a sample material 15 , in place on surface 16 , to produce ions of the sample material, some of which are detached from the surface and admixed with the gas adjacent the surface.
- a stream of gas is then pulled into a port means 18 of ion collection means 80 leading to ion detection and identification means 20 by action of pump 22 .
- ion production means 14 which suitably may be constructed as a cylinder having a wall member 120 and arranged for generally axial flow of gases therethrough.
- a corona discharge is produced at the upstream end by ion production means 14 in space 24 located between corona discharge needles 26 and corona disk electrode 27 .
- a first stream of gas 29 suitably either helium or argon among others, and possibly containing dopant chemicals, is introduced into ion production means 14 by way of first port 31 and is passed through the corona discharge in space 24 to thereby generate relatively long-lived, metastable helium or metastable argon atoms.
- a pair of filtering electrodes, 33 and 34 is placed just downstream from the corona discharge. One of those electrodes is positively charged and the other negatively charged and the two serve to remove ions that were created in the corona discharge area but do not interact with the metastable atoms as those carry no charge.
- a reaction space 37 is provided just downstream from filtering electrodes 33 and 34 wherein gas stream 29 , carrying excited metastable atoms, mixes with a second gas stream 39 entering into space 37 by way of port 41 .
- Second gas stream 39 is preferably air, including clean dry air from a filtering device containing dessicant, but may comprise other gases or mixtures of gases depending upon the application.
- Metastable atoms of first gas 29 react with the second gas 39 to produce an array of positive and negative ions.
- the ions that are produced in space 37 are then accelerated in a downstream direction and focused into a coherent stream by action of electrodes 35 , 151 , 153 and 155 .
- a space 150 is provided adjacent the terminal end of the ion production means.
- Space 150 contains a plurality of accelerating and focusing electrodes 35 , 151 , 153 , and 155 ( FIG. 4 ), that cause the ion stream to exit the ion production means 14 at port 51 as a tight, coherent conical beam 12 .
- the terminal portion of space 150 is advantageously formed with a conical tapered wall 165 that regularly decreases in diameter from the inner side of wall member 120 to the exit port 51 .
- That structure forms a manifold 167 around the outside of wall 165 which functions to provide a flow of gas 169 from inlet 175 through a ring orifice 171 that encircles the exit port 51 , producing a generally conical gas sheath that surrounds the ion stream.
- Gas flow 169 provides a protective sheath that helps to prevent reaction of the ion beam 12 with contaminant compounds.
- FIG. 3 depicts an embodiment of the ion production means 14 in which the central portion 46 is formed as a venturi so that an air stream is drawn through port 41 into the body of means 14 by the reduced pressure created by flow of first gas stream 29 through venturi area 46 .
- a filter means 47 having an entry 48 and preferably containing a desiccant, is located upstream from port 41 so as to provide a clean air stream of uniform humidity to the ion production means. Water vapor is ionized by the excited species produced in the corona discharge so variations in humidity in the air entering means 14 can introduce undesirable variations in the ion population discharged from the unit.
- FIG. 5 is a cross-section taken along line 5 - 5 ′ of FIG. 4 .
- Means 14 in this embodiment, includes ion concentration and gas exchange means, located centrally between reaction space 37 and terminal end space 150 , that serve to strip ions from the helium stream and transfer those ions to a different gas, which suitably is purified air which may contain a dopant chemical to influence the nature of the ions.
- the ion concentration and gas exchange means is provided with a cylindrical outer wall 122 , a central, axially aligned electrode carrier 125 , and a cylindrical partition member 127 that serves to form a first annular space 129 that is open at its upstream end to accept the mixed and reacted gas from space 37 .
- a second annular space 131 is formed between partition member 127 and axial electrode carrier 125 .
- Partition member 127 is provided with two ports 133 and 135 that conveniently may be placed opposite one another to allow ion and gas flow between the first and second annular space.
- a pair of electrodes 137 and 138 having the same polarity as the incoming ions contained in the gas issuing from space 37 , is located on the inner side of wall 122 within annular space 129 just opposite ports 133 and 135 .
- An electrode 141 of opposite charge to electrodes 137 and 138 , is located on electrode carrier 125 in alignment with ports 133 and 135 .
- the ions in the gas stream within annular space 129 approach electrodes 137 and 138 , they are directed toward and through ports 133 and 135 .
- the ions are attracted toward electrode 141 which tends to pull ions from the gas in space 129 , through the ports, and into annular space 131 .
- a flow of gas is continuously introduced into annular space 131 by way of entry 143 that is located upstream of ports 133 and 135 .
- the ion-depleted gas stream is exhausted to the atmosphere by way of exhaust port 145 that is located downstream of ports 133 and 135 while the ion-enriched gas stream exits annular space 131 into the ion accelerating and focusing space 150 .
- the relative cross sectional areas of annular spaces 129 and 131 and the flow rates of the gas streams in those annular spaces can be adjusted such that the ion concentration in the gas within annulus 131 is substantially greater than that of the gas in annulus 129 . Furthermore, by maintaining the pressures of the two gas streams such that there is a small but constant bleed of gas from space 131 into space 129 , essentially all of the helium entering the system is rejected and exhausts through port 145 .
- the ion stream produced may be either positive or negative depending upon the polarity applied to the various electrodes.
- a preferred embodiment of this invention employs a laser, or other type of, range finder 49 that is mounted in fixed association with ion production means 14 .
- This embodiment is especially desirable in those instances wherein the device of this invention is configured as a compact, light, hand-held detector system for use in screening individuals, luggage, clothing and similar items without physical contact of any sort.
- Range finder 49 continuously determines the distance between the exit port 51 of the ion production means and the surface sample 15 .
- Information stream 52 from the range finder is transmitted to processing unit 53 which may then use that information to adjust the focusing and acceleration functions of electrodes 35 , 151 , 153 , and 155 , so as to maintain the area of surface 16 impacted by the conical ion beam relatively constant as the distance between exit port 51 and surface sample 15 is changed. That result is accomplished by increasing the apex angle of the ion beam at short distances, on the order of an inch or so, between port 51 and surface sample 15 , and decreasing the apex angle at greater distances, up to five to six inches between the port and surface sample.
- feedback 55 from spectrometer 20 may be processed in a second controller means 56 to maximize ion content of sample gas entering the spectrometer by changing the attitude and location of ion collection/spectrometer entry port 18 relative to the exit port 51 of ion production means 14 through action of servo means 57 .
- Ion detection and identification means 20 is preferably a miniaturized differential mobility spectrometer that is schematically illustrated in FIGS. 6 and 7 of this application and that is described in U.S. Pat. No. 6,512,224 to Miller et al, the entire disclosure of which is incorporated herein by reference.
- the differential mobility spectrometer that is described in the Miller et al patent is commercially available from Sionex Corporation. It is microfabricated in a manner analogous to the manufacture of a printed circuit and is in the form of a planar array having an overall size on the order of 36 ⁇ 72 mm, with a plate spacing of about half a millimeter.
- Detector 20 is shown in schematic cross-section in FIGS. 6 and 7 and comprises a microfabricated planar array that forms an ion filter having no moving parts.
- a stream of ions 60 carried in a gas, is flowed between filter plates 62 and 63 of sensor 20 .
- An asymmetric oscillating RF field 65 is applied perpendicular to the ion flow path 67 between filter plates 62 and 63 to impart a zigzag motion ( FIG. 6 ) to the ions.
- a DC compensation voltage is applied between plates 62 and 63 to control the motion of the ions such that some travel all the way through the plate array and are detected by electrodes 70 and 71 , while others are directed to one or the other of plates 62 and 63 and are neutralized.
- Two or more detector electrodes are located downstream from the filter plates.
- One of the electrodes, 70 is maintained at a predetermined voltage while the other of the electrodes 71 is typically at ground. Electrode 70 deflects ions downward to electrode 71 where they are detected.
- either electrode 70 or electrode 71 may be used to detect ions or multiple ions may be detected by using electrode 70 as one detector and electrode 71 as a second detector. In this way, both positively and negatively charged ions can be detected simultaneously.
- the output of the detector electrodes is transmitted to an electronic controller 75 where the signal is amplified and analyzed according to algorithms that serve to identify the ion species.
- an entry port electrode 77 to which either a positive or negative charge may be applied so as to attract oppositely charged ions toward and into the ion detection means 20 .
- Ion detection sensitivities may be increased as much as 10-fold or more through use of an ion inlet and concentration means 80 shown in diagrammatic cross section in FIG. 8 .
- This device may comprise port means 18 of FIG. 1 , and includes the functional equivalent of the ion concentration and gas exchange means employed in the ion production device that was illustrated in FIGS. 4 and 5 . It serves to draw sample ions into the inlet and to change the gas containing the ions from ambient air collected at and near the sample and of uncontrolled composition, to air or other gas of defined composition, alone or in combination with other gases, including dopants such as methylene chloride and the like, which can be ionized using a very small UV lamp elsewhere in the detector.
- Means 80 includes an inlet portion 201 that comprises a conduit having an upper wall 82 and a lower wall 84 .
- a conductive, apertured entry 203 is provided at one end of the conduit to which a polarity and potential sufficient to attract the incoming ions contained in adjacent reaction cloud 111 is applied.
- Electrodes 206 and 207 are disposed around the inner periphery of conduit 201 just downstream of entry 203 and are of polarity and potential sufficient to attract and focus incoming surface analyte ions.
- the potential applied to entry 203 and to electrode 206 are similar and that of 207 is higher.
- Additional electrodes 209 and 210 are disposed around the inner periphery of conduit 201 further downstream from the entry. These last electrodes carry a controllable potential that is of the same polarity as is the incoming ion stream and serve to focus the ions into the central area of the conduit.
- Reaction cloud 111 comprises a mixture of the gas issuing from the ion production means 14 and the ambient atmosphere, and contains sample ions formed by interaction of energetic ions from means 14 with sample materials 15 in place on surface 16 .
- a stream of gas 91 comprising reaction cloud 111 , is drawn through conduit 201 by action of pump 22 ( FIG. 1 ), and the ion concentration in that gas stream is increased due to the attractive influence of the potential field created by the charge applied to inlet 203 .
- the gas exchange portion of means 80 comprises a two-chamber conduit formed by a partition wall portion 85 that is disposed exterior to and generally parallel with conduit walls 82 and 84 .
- An orifice 87 located between the chamber ends is arranged to allow gas flow between upper chamber 88 and lower chamber 89 .
- a flow of ions in the ambient sample atmosphere 91 is directed into the entry of the upper chamber 88 .
- the ambient sample atmosphere with ions removed exhausts from the chamber 88 end at 92 .
- a second gas stream 94 for example, suitably preconditioned dry air, is directed into the entry of the lower chamber 89 .
- Gas stream 94 passes through chamber 89 and the exiting flow 95 is then directed into the entry of ion detection means 20 .
- the cross sectional area of chamber 88 relative to chamber 89 and the flow rate of sample atmosphere 91 relative to the flow rate of the second gas stream 94 are adjusted such that there is a small and constant bleed 97 of gas from the lower chamber 89 into the upper chamber 88 through the orifice 87 .
- a first electrode 98 having the same polarity as the incoming ions in sample stream 91 is located within chamber 88 above the orifice 87
- a second similar electrode 99 having a polarity opposite to the incoming ions, is located within chamber 89 below the orifice.
- the ions in sample stream 91 approach electrode 98 , they are repelled and are directed toward and through orifice 87 .
- the ions are attracted toward electrode 99 , which tends to pull ions from sample stream 91 through the orifice and into gas stream 94 .
- a preferred ion detector 20 is a microfabricated differential mobility spectrometer that typically has a plate spacing on the order of half a millimeter. That small plate spacing allows use of much higher electric fields than are usual in other detector systems such as those employing ion mobility spectrometers; e.g. as high as about 35,000 V/cm compared to about 600 V/cm. Higher variable electric fields allow the changes in the mobility of ions as a function of field strength to be exploited to enhance selectivity and resolution. However, the maximum electric field is limited by the voltage at which arcing between the plates occurs with resultant destruction of the detector. Arc over occurs at a much lower voltage with helium or argon than with air. Consequently, removal of helium and argon from the sample gas stream that is analyzed allows for operation of the detector at higher field voltages thus further increasing the selectivity of the system.
- the ion production means of this invention does not use radioactive elements for ion creation and is therefore free of the regulatory burden imposed on devices employing radioactive sources.
- the corona discharge production of metastable helium atoms followed by the reaction of those metastable atoms with air to produce ions which in turn are used to ionize molecules of the sample is on the order of 1000 times more efficient than are those approaches that use the standard radioactive nickel or americium sources.
- the system of this invention creates far more ions of the sampled material than do conventional ion sources and because the preferred detector examines far more of the ions that are produced, fewer false positives or negatives result and superior resolution of targeted chemical ions from interferents is obtained.
- both the ion source and the ion collection means and detector are operated in a pulsed cyclic mode.
- ion production and collection can be seen as two half cycles, the first half cycle being diagrammed in FIG. 9 and the second half cycle being diagrammed in FIG. 10 .
- a gas stream 101 carrying negatively charged reactant ions issues from the outlet 51 of the ion production device 14 and is directed toward surface 16 having a sample material 15 deposited thereon. Stand off distance between outlet 51 and surface 16 may conveniently range from less than one inch to six inches or more, thus allowing a non-contact and non-destructive inspection of the surface for the presence of the sample material.
- Ion production device 14 is configured to produce reactant ions of predominately one charge; in this case it is producing negative ions.
- a negative potential is applied to an electrode 106 that is located at the tip of outlet 51 . That negative charge acts to accelerate the negative ions contained in the gas stream issuing from outlet 51 toward surface 16 .
- a similar electrode 108 is located at the tip of ion collection means and/or detector inlet 109 .
- Inlet 109 may comprise either the inlet to ion detection means 20 , in which case electrode 77 of FIG. 7 and electrode 108 are the same, or it may comprise an inlet means 203 to ion concentrator 80 of FIG. 8 .
- the potential on electrode 108 at this stage of the cycle is zero or ground potential.
- the negative pressure at the detector inlet 109 may be decreased during this time so as not to pull gas and ions from stream 101 toward the detector inlet.
- Electrode 106 remains at a negative potential and electrode 108 remains at zero potential.
- a reaction cloud 111 typically comprising a mixture of air and helium and containing negatively charged surface sample ions, among other species has formed above the surface that is being examined.
- FIG. 9 c the reactant ion production pulse has ended.
- a negative potential is maintained on electrode 106 while the potential on electrode 108 is changed from zero to positive and the negative pressure at the detector inlet is increased.
- Electrode 108 is shaped and charged to produce an electric field that has the effect of drawing the ions in reaction cloud 111 toward the detector inlet. As shown in FIG.
- the ion cloud pulse is delivered first to ion concentrator 80 and then to the differential mobility spectrometer.
- the second half cycle is the obverse of the first half cycle, and is diagrammed in the steps shown in FIGS. 10 a through 10 d .
- Ion production device 14 is now configured to produce positive reactant ions, which are carried in the helium stream 101 issuing from outlet 51 .
- the potential applied to electrode 106 remains positive throughout the entire half cycle, first accelerating positive ions toward the surface 16 and thereafter repelling the reaction cloud 111 .
- Flow of the reactant ion stream 101 is ended after formation of the reaction cloud.
- the potential applied to electrode 108 is briefly switched to negative ( FIG. 10 c ).
- the shape and charging of electrode 108 is sufficient to attract positive ions, including those formed from the sample material 15 , toward inlet 109 .
- a negative pressure is applied to inlet 109 , drawing the reaction cloud toward and into the inlet.
- the potential of electrode 108 can be then switched from negative to neutral ( FIG. 10 d ) before the ion cloud reaches the electrode so as to minimize destruction of the positive ions.
- the potential on electrode 108 can be left on and the collisions of ions with walls avoided by focusing the ions within the ion collection means as shown in FIG. 8 . Thereafter, the reaction cloud is delivered as a pulse to the ion concentrator or detector.
- Cycle length can be varied over a fairly large range as the time for completing a cycle depends upon a number of controllable factors. Those factors include standoff distance between the ion outlet and the sample surface, gas flow rate delivered by the ion production means, and the configuration of the gas exit orifice. Generally speaking, a cycle can be completed in as little as 0.5 seconds or extended to several seconds in length. It is usually advantageous to maintain cycle times as short as possible. Cycle time can be controlled by feedback from the differential mobility spectrometer. The timing of detection of certain reactant ions indicates the place in the cycle, allowing for automatic adjustment of the controls determining cycle time.
- FIG. 11 is a schematic diagram of one embodiment of this invention in which all of the system components are assembled as a fully portable, hand-held detector 180 that contains its own helium supply.
- a subassembly 183 that includes those components within the dashed line 182 defines a common platform that can be used for each of the different configurations of the system.
- This common platform includes air and helium valving and gas flow control means 184 , reactant ion production means 14 , sample ion collection, detection and identification means 20 , and an operator interface and control unit 186 .
- An on-board helium supply 190 conveniently in the form of a disposable cartridge containing pressurized gas, provides an adequate supply for a limited number of analyses and thus is suitable for use by first responders, law enforcement and military personnel.
- a computer 192 together with its operating software controls the functioning of the system including helium and air flows and the operating parameters of the reactant ion source 14 that in turn depend upon whether the system is being operated in a continuous or in a cyclic mode.
- the computer also uses information from rangefinder 49 (standoff distance from the ion source outlet to the surface that is being investigated) and sensor information to control reactant ion production and surface sample ion collection to maximize both.
- the software carried in computer 192 employs a number of different algorithms to distinguish between and to identify ions and charged molecular fragments that result from the impingement of reactant ions, in ion stream 101 , upon a surface 16 that has deposited thereon chemical compounds or other agents of interest or concern.
- a number of different algorithms are carried in the computer, a different algorithm for each of different classes of materials.
- algorithm 1 is specific to chemical warfare agents
- algorithm 2 is specific for explosives
- algorithm 3 is specific for drugs of both the prescription and illegal varieties
- algorithm 4 is specific for toxic industrial chemicals and other toxic industrial materials.
- the system also requires a power source 195 that may include both batteries and a transformer-inverter for AC use.
- Readout means 198 is arranged to report the results of an analysis, and may be adapted to provide data either in visual form or as a printout. All of the system components reside within a case 199 , which can be easily carried and maneuvered during use.
- the system of FIG. 11 may also be configured in another mode in which the helium supply tank is separated from the other system components with the helium being supplied from a larger tank carried separately by the system operator.
- a tank as small as 21 inches in height and 3.5 inches in diameter and weighing on the order of ten pounds, can contain as much as 550 liters of helium. That would allow up to about 30 hours of continuous operation at a use rate of 300 ml/min.
- a limited portable configuration may also be employed.
- the common platform as defined in FIG. 11 , is assembled within a separate case that is tethered to a stationary base by means of a flexible cable for passing electrical signals and a flexible hose for supplying helium.
- This configuration provides mobile detection and surface interrogation capability within a fixed radius of a stationary point and avoids any weight or size limitations on the choice of a computer, its operation/detection software, power source and display/printer/data storage devices. It can also better accommodate the largest and most robust libraries of algorithms for distinguishing explosives, drugs, chemical warfare agents, and toxic industrial chemicals from interferents and innocuous substances.
- This configuration is especially advantageous for use at security and transportation checkpoints to monitor people, baggage, cargo, and material surfaces, as well as for the examination of baggage or incoming deliveries on conveyor belts, and for military, law enforcement, prison and industrial monitoring.
- the common platform in whole or in part, and in conjunction with other parts of this configuration, can be used to examine items passing before it, whether such item be baggage or industrially produced items such as pharmaceuticals in order to determine the presence or absence of certain target chemicals in each different use.
- the system can be deployed as a non-portable, bench top detector mode. This arrangement is particularly useful in those applications requiring high volume examination or scanning of field-collected samples, or in those instances in which a detailed scanning and examination of suspect objects is needed
Abstract
Description
- 1. Field of the Invention
- This invention relates to a method and apparatus for the direct, non-contact, real-time sampling and detection of minute quantities of materials on surfaces.
- More particularly, this invention relates to a method and apparatus for producing ions from targeted sample molecules on or above a surface that is spaced apart from the apparatus and for detecting and identifying those ions, all without contacting the surface.
- 2. Description of Related Art
- Military and security needs, law enforcement concerns and environmental monitoring all require a capability to sample and detect minute quantities of explosives, drugs, chemical and biological agents, toxic industrial chemicals, and other targeted compounds of interest residing on or in a variety of materials and surfaces. Most users desire a fast, portable, simple, operator friendly detector that combines different detection capabilities in a single unit and that is capable of directly and automatically acquiring samples from surfaces, identifying targeted substances in those samples, and providing immediate operator notification that such substances are present or not.
- Most explosives, chemical warfare agent, toxic industrial chemical and illicit substance detectors in use for security purposes depend upon the vapor pressure of the targeted material for detection. If vapor pressures of chemicals of interest are very low, they are undetectable by traditional screening methods or vapor must be produced from these materials. Consequently, using current technology, sample chemicals must be first collected from a surface by wiping or vacuuming. The wipes or vacuum filters must then be heated and the vapor introduced to a vapor detector for detection and identification of the chemicals present. These methods are time consuming, expensive and highly dependent upon trained operators capable of near perfect consistency in obtaining samples. These factors limit screening to only a small portion of the samples that should be examined.
- The present invention provides a complete means to scan surfaces such as paper, plastics, skin, glass and textiles from variable distances and determine in seconds if targeted chemicals or materials are present, completely independent of the vapor pressures of such chemicals. Currently available detectors generally create ions of the vapors of targeted chemicals and other chemicals taken into the body of the detector, then separate the ions and detect, identify and provide notification of the presence of any targeted chemicals. The present invention overcomes this limitation by creating ions from sample chemicals exterior to the detector, on surfaces, and draws these ions into the detector for separation, detection, identification and notification.
- In order to do this in an easy to use, yet economical configuration, reactant ions are created within the detector from a constant supply of conditioned air or other gas. These reactant ions are focused and accelerated as they leave the detector. The reactant ion stream impacts the chemicals on a surface exterior to the detector and creates surface sample chemical ions. These ions are drawn into another part of the detector, using electronic means to control ion movement and collection. Once within the detector, the surface sample chemical ions are separated from the ambient air in which they are collected, and simultaneously moved and concentrated in a stream of constant composition air. The ions are then detected and identified after movement into a micro differential mobility spectrometer having no moving parts and made much like an integrated circuit.
- In seeking to develop a single device that would directly ionize samples on surfaces and subsequently detect and identify these sample ions, use was made of several precedents. For example, ion mobility spectrometers require an ion source, which may be a radioactive ionization source (β-emitter or electron producer) such as 63Ni. Because of the regulations associated with obtaining, transporting and maintaining equipment with radioactive sources, alternative ionization sources such as corona discharge ionization sources are preferred. Such a corona discharge is described in U.S. Pat. No. 6,225,623. Corona discharge units have been and are widely used with helium gas to produce long-lived metastable helium atoms. These excited state helium atoms are used to transfer energy to neutral molecules, thereby ionizing such neutral molecules. An exemplary detector that uses a corona discharge ionization source is described in the Cook patent, U.S. Pat. No. 4,789,783. Such corona discharge ionization detectors are commercially available from Finnegan, GOW-MAC, VICI and others.
- A variation of the corona-type ionization source is described in International Application No. WO 2004/098743 A2. The source comprises a chamber having an inlet port and an outlet port for passage of a carrier gas, and a pair of electrodes arranged to create a corona discharge within the chamber. The carrier gas, helium or nitrogen, is passed through the corona discharge causing formation of, among other species, neutral, excited state, metastable species of the carrier gas. Those excited state carrier gas molecules upon leaving the device then contact the sample, or analyte, and by transfer of energy from the excited state carrier gas molecules to analyte molecules, produce analyte ions. The analyte ions in the carrier gas are then passed to a charged particle or ion sensor, which may be the sensing element of a mass spectrometer or an ion mobility spectrometer. In this teaching, the helium metastable atoms leave the confines of the device and subsequently react with surface materials to produce surface sample ions.
- In the present invention, the neutral helium metastable and energetic atoms, freed of any ions produced in the corona discharge by ion filters, are then reacted with the chemical components of air or other gases such as dopants, introduced within the device, causing the formation of reactant ions, such as O2 − and H3O+, and electrons within the device. It should be noted that neutral metastable helium atoms can interact with other metastable atoms and with neutral ground state atoms to produce charged species. So, even if ion filters are used at this stage, ions can still be produced. The advantage of using filters is that they remove the ions produced during passage of the gas through the corona discharge. Subsequent charged species production results only from the interactions noted above. Alternatively, if ion filters are not used, ions produced in the corona discharge, along with energetic neutral species, are reacted with the chemical components of air or other gases, introduced within the device, causing the formation of reactant ions, such as O2 − and H3O+, and electrons within the device. This transfer and downhill flow of energy from (1) the corona to energetic atoms and ions, then (2) from energetic atoms and/or ions to ions of introduced gases, results in the production of reactant ions that can be controlled and used in “soft” ionization processes to produce significant populations of molecular ions and clusters from a very wide variety of chemicals.
- Unlike helium metastable atoms, which carry no charge, these reactant ions are positively or negatively charged and can be focused and accelerated within the device, and after they leave the device, they can be moved towards or away from different parts of the device depending upon the potential applied to that part of the device. Furthermore, these reactant ions can react with most chemicals to produce ions from those chemicals. The electrons produced can also react with gases to produce reactant ions.
- The capability to control the reactant ions through focusing and acceleration provides several useful practical advantages over other methods. First, automated distance information from a rangefinder can provide feedback control to the ion focusing and accelerating portions of the invention. For example, by using such feedback control to direct the electronic focusing to vary the width of the ion stream leaving the ion production device, the reactant ions created within the invention can be focused on a surface such that the same amount of ions per unit area hit the surface independent of the distance between the detector and the surface. This allows the operator freedom of movement of the detector away from and towards the surface with assurance that, regardless of position, the same amount of detector initiated reactant ions will generate the same amount of sample ions on the surface, and ultimately, the same sensor-driven signal within the detector. Second, the reactant ions created within the invention are those well known to react with a wide variety of chemicals of interest, to form predominantly molecular ions. Molecular fragmentation is kept to a minimum in this “soft” ionization process. This greatly simplifies the detection and identification process. Third, the reactant ions emitted from the detector can be confined within a sheath gas such that, in the transit between detector and surface, the integrity of the detector originated ion population is largely maintained and admixing with the ambient air between the detector and the surface sample is kept to a minimum.
- Turning to the detection of the produced surface sample ions, a mass spectrometer would appear to be ideal because of its high sensitivity and resolution or selectivity. However, mass spectrometry requires large, heavy and expensive equipment making the technique impractical for applications that require portability. The most widely used analytical systems for detecting and monitoring explosives and chemical warfare agents, both by the military and for airport security, employ ion mobility spectrometry (IMS). Ion mobility spectrometers function by pulling a gas that contains molecules of the compounds of interest through an ionization source and then moving the ions produced through a sensor. Both the ionization source and the sensor are commonly incorporated within a cylindrical drift tube, which is divided into two parts. The first, or reaction, region contains the ionization source and is separated from the drift region by an electrical shutter or ion gate. In all cases, the sample molecules are directly subjected to the ionization source and, depending upon the sample and the intensity of the source, a wide variety of molecular fragments, as well as simple ions, are produced. Under the influence of an electric field, the mixture of reactant and product ions reaches an ion gate that separates the reaction region and the drift region. With a bias voltage applied, the ions are attracted to the ion gate and lose their charge. Then the bias is briefly turned off, and ions are transmitted into the drift region of the cell. The smaller, more compact ions have a higher mobility in the electrical field than the heavier ions, and therefore traverse the region and collide with the collector plate in a shorter time. The collector current is then amplified. Its magnitude, as a function of time, is proportional to the number of ions arriving at that moment. The time-of-flight or mobility enables the identification of different chemicals. There are several significant drawbacks to IMS including:
-
- Typical ion mobility spectrometer analysis cycles require 5-8 seconds from introduction of sample to alarm notification
- The percentage of ions produced that are actually detected is as low as 1% due to the ion gate, resulting in lower sensitivity
- Resolution among different ions is dependent upon the length of the drift region, making it difficult to miniaturize
- Reduction in the cross sectional area of the drift tube also decreases sensitivity, again making it difficult to miniaturize
Despite those limitations, ion mobility spectrometers may be usefully employed with the ion source of this invention to produce portable, non-contact sampling systems.
- Another charged particle or ion sensor that is coming into use employs differential mobility spectrometry (DMS). An example of a differential mass spectrometer is the MicroDMx manufactured by Sionex Corporation. This device has no moving parts and is microfabricated. Its small size allows for extremely fast clear down times and very rapid responses to the presence of ions. In differential mobility spectrometry, selectivity is significantly enhanced relative to other techniques of ion resolution and detection. DMS exploits the way in which the mobility of ions changes in response to changes in an applied variable high electric field, and this provides substantially more information relating to a molecule's identity than other methods, consequently leading to a significant reduction in false positives. Differential mobility spectrometry can detect positive and negative ions simultaneously and has superior sensitivity and selectivity capabilities relative to more commonly used sensors such as ion mobility spectrometers. DMS achieves superior selectivity relative to simple time-of-flight information employed in other detectors by using placement of ions within four-dimensional space constructed to examine changes in ion mobility as a function of changes in high electric field strength. Detection and identification are rapidly made and notification of presence or absence of targeted materials given in near-real time. Sensitivity is enhanced as well because as a range of compensation voltages in a DMS device are scanned the actual percentage of ions detected for any type of ion species is significantly higher (>10×) than in conventional IMS. The capability of DMS to continuously accept and analyze sample ions, without the need for the ion-gate used in IMS devices, also increases the percentage of ions detected and consequently increases its overall sensitivity. Therefore, the sensitivity of DMS is higher than that of conventional IMS, and DMS sensors have the capability to detect compounds in the parts per trillion ranges. Differential mobility spectrometry can be used to detect positive and negative ions simultaneously. This is important in cases where all surface sample ions created would be collected at the same time, or where positive and negative ions would be alternately collected for extremely short times. These attributes of DMS are very important for the detection of explosives or other dangerous or controlled materials on clothing, baggage, paper, etc. at security checkpoints. Detection of such materials must be rapid, but also must be done with virtually no false negatives such that these materials go undetected when actually present, creating a potentially dangerous situation. There must also be virtually no false positives such that materials are detected when none are present, thereby closing down the checkpoint while the false positive is verified as erroneous. The selectivity of DMS for certain materials such as explosives can be enhanced by transferring ions from an incoming ambient air stream to an air stream of controlled composition, possibly containing a dopant chemical to further control the nature of the ion species in the stream.
- Having considered the ion production and ion detection portions of the invention, it is then necessary to manage, in a complementary manner, the movement of the reactant ions from the detector to the surface and the subsequent collection and concentration of surface sample ions in another part of the detector in order to most efficiently use the ions produced within the invention and in order to maximize sensitivity of the invention. Issuing reactant ions of alternating charges as a function of time from the ion production device and biasing the ion outlet to the same charge of the reactant ions so the ions are “pushed” away from the ion outlet and towards the surface can accomplish this. In synchrony with the changing biasing of the ion production device, the ion collection device undergoes programmed biasing aimed at providing sufficient charge opposite to that of the produced surface sample ions, thereby “pulling” these ions toward the collection device and into the sensor for detection and identification. The maximum possible number of collected ions must reach the sensor to attain the highest sensitivity. In order not to lose ions through collisions with walls within the detector, the ions are focused such that they are transported without touching the walls. The possibility exists that reactant ions of one charge could form both positively and negatively charged surface sample ions. In this case, for each “burst” of reactant ions released on the surface sample, there would be two cycles of ion collection—one positive and one negative. This allows for the real-time collection of maximum information from the surface sample. The continuous detection of residual or unreacted reactant ions by the differential mobility spectrometer provides a means for feedback and other control of the detection system. For example, such feedback can be used, in conjunction with the distance from the detector reactant ion production device to the surface (provided by a rangefinder) to control the timing of changes of potential applied to the ion collection inlet, relative to those changes of potential controlling the production of reactant ions, as the distance between the detector and surface is changed. This has the practical effect of providing assurance that relatively the same number of ions is detected by the detector as it is moved toward or away from the surface. The operator, therefore, does not have to keep the detector at a fixed distance from the targeted surface and allows for freedom of movement of the detector toward or away from the surface with assurance that targeted surface materials will still be detected with relatively the same certainty. In the absence of a surface, i.e. if the targeted chemical is contained in the ambient air, feedback control without using the rangefinder but using the DMS signal, can be used to control the density of reactant ions projected from the ion production means, thereby controlling the overall sensitivity of the detector.
- Using a means to generate ions of targeted chemicals on surfaces coupled with a small fast sensor with excellent sensitivity and selectivity, and the means to use distance and sensor information as feedback to control the entire process, provides the elements of a detector that can be used to close security loopholes. It will enable the rapid screening of the surfaces of people, baggage, cargo, parcels and vehicles at government and private facilities, transportation centers, checkpoints and borders, among others. It will also find use in substantiating illegal activities by facilitating the rapid and accurate detection of chemical warfare agents (CWAs), explosives and illicit substances and to verify decontamination efforts are successful by military personnel. Key features of the invention are means to control, focus and accelerate the detector originated reactant ions responsible for producing surface sample ions from chemicals on surfaces, and the coordination of these events with the rapid collection of the surface originated ions in high yields for detection and identification by the sensor. The capability to apply roughly the same amount of reactant ions to the same surface area regardless of the distance of the detector from the surface allows the operator to scan the surface from variable detector—surface distances and obtain the same result, rather than be constrained to holding the detector at a fixed, close distance from the surface.
- Hence, it is an object of this invention to provide an ion production and sensor system that operates by impacting a reactant ion stream upon a surface to form ions of sample compounds carried on that surface, to collect at least some of the sample ions that are formed, and to pass those ions into, for example, a differential mobility spectrometer to identify and quantify the sample compounds.
- Another object of this invention is to provide an extremely sensitive, fully portable, hand-held detector that can identify and quantify compounds such as drugs and chemical warfare agents in place on surfaces without physical contact of those surfaces.
- Yet another object of this invention is to detect equally well the presence of sample compounds having extremely low or hugely different vapor pressures without physical contact of the surface that carries the sample compounds.
- It is a further object of this invention to provide an improved reactant ion production means that can direct a beam of reactant ions upon a surface to produce sample ions from materials on the surface at atmospheric pressure and without physical contact.
- Other objects and advantages of this invention will be evident from the following description of certain preferred embodiments.
- The detector system of this invention includes two major parts. First is a reactant ion production device having the capability to produce reactant ions from introduced air or other gases, and to filter, focus and accelerate such reactant ions constrained within a sheath gas or not as appropriate, toward a surface, generating surface sample ions from the chemicals on that surface. Second is an ion collection device that collects surface sample ions produced by the interaction of reactant ions with sample chemicals on the surface. The ion collection device has the capability to transfer such sample ions from the ambient air in which they are collected to a controlled air stream, to introduce reactant gases or dopants that can modify the structure, charge and/or adduct formation or dissociation of the sample ions, and to introduce the ions into a differential mobility spectrometer. Events in the ion production and ion collection devices are fully coordinated to maximize sample ion production and collection. Feedback controls, using information from a rangefinder and the spectrometer or sensor, enable similar ion detection results to be obtained regardless of the distance between the detector and the surface.
-
FIG. 1 is a schematic representation showing the arrangement of the reactant ion production and surface sample ion collection, detection and identification means according to this invention; -
FIG. 2 is a schematic representation of a first reactant ion production means of theFIG. 1 system; -
FIG. 3 is a schematic representation of another embodiment of the reactant ion production means ofFIG. 2 ; -
FIG. 4 is another embodiment of the reactant ion production means ofFIGS. 2 and 3 , including a means for concentrating ions and changing the ion carrier gas as is illustrated inFIG. 8 ; -
FIG. 5 is a cross sectional view of the ion production means ofFIG. 4 taken along line 5-5′; -
FIG. 6 is a diagrammatic representation of a surface sample ion detection and identification means according to the present invention; -
FIG. 7 is a partial, cross sectional representation of the surface sample ion detection and identification means ofFIG. 6 ; -
FIG. 8 is a cross-sectional representation of an ion inlet arranged with a surface sample ion concentration and change of ion carrier gas means for use with the detection and identification means ofFIGS. 6 and 7 ; -
FIGS. 9 a through 9 d depict the first half of a cycle of the production of ions, showing the production of negatively charged reactant ions, creation of negatively charged surface sample ions and collection of such surface sample ions using the reactant ion production means ofFIGS. 2, 3 and 4, and the surface sample collection, detection and identification means ofFIGS. 7 and 8 when operated in a pulsed mode; -
FIGS. 10 a through 10 d depict the second half of a cycle of the production of ions, showing the production of positively charged reactant ions, creation of positively charged surface sample ions and collection of such surface sample ions using the reactant ion production means of FIGS. 2 3 and 4, and the surface sample collection, detection and identification means ofFIGS. 7 and 8 when operated in a pulsed mode; and -
FIG. 11 is a generally schematic diagram of the arrangement of components in an operating system for a detector according to the teachings of this invention. - In a broad sense, this invention can be viewed as a method and means for conducting a three-step energy transfer process that may then be followed by an analytical procedure. Energy is applied to a first gas by means of a corona discharge, forming ions and other energetic species of that gas. The energetic species of the first gas then transfer energy to a second gas, which must have at least one component with an ionization potential, or ionization energy, less than that of the energetic species of the first gas so as to produce reactant ions of the second gas. Those reactant ions are caused to impact upon a surface, reacting with chemicals or other materials on the surface to produce analyte ions that are collected, detected and identified.
- A significant advantage of this downhill energy flow is that it utilizes energy from an inexpensive, relatively uncontrolled high energy source (corona discharge) and converts it into energetic species that provide a “soft” ionization of analytes. That is, the reaction of
Gas 2 reactant ions with analytes produces mainly molecular ions rather than ionized structural fragments. This simplifies the detection and identification process in a wide variety of situations. - Another advantage to using intermediate gases to ionize surface analytes is that the use of different gases can affect the population of surface analytes that is ionized, as well as the nature of the surface analyte ion ultimately detected. For example, the corona discharge can be used to produce energetic helium metastable atoms (ionization potential=20.6 e.V.). Then, these energetic atoms can transfer energy to the components of air having lesser ionization potentials (nitrogen, 15.6 e.V.; oxygen, 12.1 e.V.; water, 12.6 e.V.), producing reactant ions. These reactant ions can ionize a wide variety of organic chemicals. Selectivity can be achieved by changing the gas from air to other gases having different ionization potentials, such as ammonia, 10.2 e.V.; acetone, 9.7 e.V.; or di n-propylamine, 7.8 e.V. Reactant ions from each of these gases would ionize organic chemicals having ionization potentials less than that of the respective gas. This provides for selectivity based on ionization potential. Furthermore, the gas ions or neutral species can combine with the surface analyte ions to produce ion/molecular clusters that can aid in analyte ion identification and separation.
- Electronic potentials at different places are used to manipulate the types and populations of reactant ions formed and issued from the reactant ion production device and of the types and populations of surface sample ions collected by the surface sample ion collection device. Also, real-time distance of detector to surface information, and detector sensor information provide automatic feedback control of these potentials. This feedback control manages and maximizes the instantaneous active interplay between the detector and the surface sample under investigation. On one hand, the reactant ion density put on the surface sample is maintained relatively constant and independent of working distance between the detector and the surface sample. On the other, the collection efficiency of the surface sample ion collector is optimized and collected ion loss prior to entry into the sensor is minimized. These events are automatically managed and coordinated such that operator input to the process is not necessary.
- Turning now to specific embodiments of the invention, the
detector system 10 ofFIG. 1 operates at ambient pressure, without sample contact, by producing astream 12 of either ions or a mixture of ions and metastable excited state molecules, in ion production means 14.Stream 12 is then directed toward asample material 15, in place onsurface 16, to produce ions of the sample material, some of which are detached from the surface and admixed with the gas adjacent the surface. A stream of gas is then pulled into a port means 18 of ion collection means 80 leading to ion detection and identification means 20 by action ofpump 22. - Referring now to
FIGS. 2, 3 and 4 as well as toFIG. 1 , there is shown various embodiments of ion production means 14 which suitably may be constructed as a cylinder having awall member 120 and arranged for generally axial flow of gases therethrough. A corona discharge is produced at the upstream end by ion production means 14 inspace 24 located between corona discharge needles 26 andcorona disk electrode 27. A first stream ofgas 29, suitably either helium or argon among others, and possibly containing dopant chemicals, is introduced into ion production means 14 by way offirst port 31 and is passed through the corona discharge inspace 24 to thereby generate relatively long-lived, metastable helium or metastable argon atoms. A pair of filtering electrodes, 33 and 34, is placed just downstream from the corona discharge. One of those electrodes is positively charged and the other negatively charged and the two serve to remove ions that were created in the corona discharge area but do not interact with the metastable atoms as those carry no charge. - A
reaction space 37 is provided just downstream from filteringelectrodes gas stream 29, carrying excited metastable atoms, mixes with asecond gas stream 39 entering intospace 37 by way of port 41.Second gas stream 39 is preferably air, including clean dry air from a filtering device containing dessicant, but may comprise other gases or mixtures of gases depending upon the application. Metastable atoms offirst gas 29 react with thesecond gas 39 to produce an array of positive and negative ions. The ions that are produced inspace 37 are then accelerated in a downstream direction and focused into a coherent stream by action ofelectrodes conical stream 12 that can be focused to form acone 43 with a small apex angle, or to form acone 45 with a larger apex angle. - A
space 150 is provided adjacent the terminal end of the ion production means.Space 150 contains a plurality of accelerating and focusingelectrodes FIG. 4 ), that cause the ion stream to exit the ion production means 14 atport 51 as a tight, coherentconical beam 12. The terminal portion ofspace 150 is advantageously formed with a conical taperedwall 165 that regularly decreases in diameter from the inner side ofwall member 120 to theexit port 51. That structure forms a manifold 167 around the outside ofwall 165 which functions to provide a flow ofgas 169 frominlet 175 through aring orifice 171 that encircles theexit port 51, producing a generally conical gas sheath that surrounds the ion stream.Gas flow 169 provides a protective sheath that helps to prevent reaction of theion beam 12 with contaminant compounds. -
FIG. 3 depicts an embodiment of the ion production means 14 in which thecentral portion 46 is formed as a venturi so that an air stream is drawn through port 41 into the body ofmeans 14 by the reduced pressure created by flow offirst gas stream 29 throughventuri area 46. This arrangement avoids the need for a pump or other means to provide air to the device. A filter means 47, having anentry 48 and preferably containing a desiccant, is located upstream from port 41 so as to provide a clean air stream of uniform humidity to the ion production means. Water vapor is ionized by the excited species produced in the corona discharge so variations in humidity in the air entering means 14 can introduce undesirable variations in the ion population discharged from the unit. - Yet another embodiment of the ion production means 14 is illustrated in
FIGS. 4 and 5 .FIG. 5 is a cross-section taken along line 5-5′ ofFIG. 4 . Means 14, in this embodiment, includes ion concentration and gas exchange means, located centrally betweenreaction space 37 andterminal end space 150, that serve to strip ions from the helium stream and transfer those ions to a different gas, which suitably is purified air which may contain a dopant chemical to influence the nature of the ions. The ion concentration and gas exchange means is provided with a cylindricalouter wall 122, a central, axially alignedelectrode carrier 125, and acylindrical partition member 127 that serves to form a firstannular space 129 that is open at its upstream end to accept the mixed and reacted gas fromspace 37. A secondannular space 131 is formed betweenpartition member 127 andaxial electrode carrier 125.Partition member 127 is provided with twoports - A pair of
electrodes space 37, is located on the inner side ofwall 122 withinannular space 129 justopposite ports electrode 141, of opposite charge toelectrodes electrode carrier 125 in alignment withports annular space 129approach electrodes ports electrode 141 which tends to pull ions from the gas inspace 129, through the ports, and intoannular space 131. Meantime a flow of gas, suitably cleaned and dried air, is continuously introduced intoannular space 131 by way ofentry 143 that is located upstream ofports space 129 to the gas flowing inannular space 131, the ion-depleted gas stream is exhausted to the atmosphere by way ofexhaust port 145 that is located downstream ofports annular space 131 into the ion accelerating and focusingspace 150. The relative cross sectional areas ofannular spaces annulus 131 is substantially greater than that of the gas inannulus 129. Furthermore, by maintaining the pressures of the two gas streams such that there is a small but constant bleed of gas fromspace 131 intospace 129, essentially all of the helium entering the system is rejected and exhausts throughport 145. The ion stream produced may be either positive or negative depending upon the polarity applied to the various electrodes. - Returning to
FIG. 1 , a preferred embodiment of this invention employs a laser, or other type of,range finder 49 that is mounted in fixed association with ion production means 14. This embodiment is especially desirable in those instances wherein the device of this invention is configured as a compact, light, hand-held detector system for use in screening individuals, luggage, clothing and similar items without physical contact of any sort.Range finder 49 continuously determines the distance between theexit port 51 of the ion production means and thesurface sample 15. Information stream 52 from the range finder is transmitted to processingunit 53 which may then use that information to adjust the focusing and acceleration functions ofelectrodes surface 16 impacted by the conical ion beam relatively constant as the distance betweenexit port 51 andsurface sample 15 is changed. That result is accomplished by increasing the apex angle of the ion beam at short distances, on the order of an inch or so, betweenport 51 andsurface sample 15, and decreasing the apex angle at greater distances, up to five to six inches between the port and surface sample. Also,feedback 55 fromspectrometer 20 may be processed in a second controller means 56 to maximize ion content of sample gas entering the spectrometer by changing the attitude and location of ion collection/spectrometer entry port 18 relative to theexit port 51 of ion production means 14 through action of servo means 57. - Ion detection and identification means 20 is preferably a miniaturized differential mobility spectrometer that is schematically illustrated in
FIGS. 6 and 7 of this application and that is described in U.S. Pat. No. 6,512,224 to Miller et al, the entire disclosure of which is incorporated herein by reference. The differential mobility spectrometer that is described in the Miller et al patent is commercially available from Sionex Corporation. It is microfabricated in a manner analogous to the manufacture of a printed circuit and is in the form of a planar array having an overall size on the order of 36×72 mm, with a plate spacing of about half a millimeter. -
Detector 20 is shown in schematic cross-section inFIGS. 6 and 7 and comprises a microfabricated planar array that forms an ion filter having no moving parts. A stream ofions 60, carried in a gas, is flowed betweenfilter plates sensor 20. An asymmetric oscillatingRF field 65 is applied perpendicular to theion flow path 67 betweenfilter plates FIG. 6 ) to the ions. At the same time, a DC compensation voltage is applied betweenplates electrodes 70 and 71, while others are directed to one or the other ofplates - Two or more detector electrodes are located downstream from the filter plates. One of the electrodes, 70, is maintained at a predetermined voltage while the other of the electrodes 71 is typically at ground.
Electrode 70 deflects ions downward to electrode 71 where they are detected. Depending upon the ion and upon the voltage applied to the electrodes, eitherelectrode 70 or electrode 71 may be used to detect ions or multiple ions may be detected by usingelectrode 70 as one detector and electrode 71 as a second detector. In this way, both positively and negatively charged ions can be detected simultaneously. The output of the detector electrodes is transmitted to anelectronic controller 75 where the signal is amplified and analyzed according to algorithms that serve to identify the ion species. Also, there may be provided anentry port electrode 77 to which either a positive or negative charge may be applied so as to attract oppositely charged ions toward and into the ion detection means 20. - Ion detection sensitivities may be increased as much as 10-fold or more through use of an ion inlet and concentration means 80 shown in diagrammatic cross section in
FIG. 8 . This device may comprise port means 18 ofFIG. 1 , and includes the functional equivalent of the ion concentration and gas exchange means employed in the ion production device that was illustrated inFIGS. 4 and 5 . It serves to draw sample ions into the inlet and to change the gas containing the ions from ambient air collected at and near the sample and of uncontrolled composition, to air or other gas of defined composition, alone or in combination with other gases, including dopants such as methylene chloride and the like, which can be ionized using a very small UV lamp elsewhere in the detector. -
Means 80 includes aninlet portion 201 that comprises a conduit having anupper wall 82 and alower wall 84. A conductive,apertured entry 203 is provided at one end of the conduit to which a polarity and potential sufficient to attract the incoming ions contained in adjacent reaction cloud 111 is applied.Electrodes 206 and 207 are disposed around the inner periphery ofconduit 201 just downstream ofentry 203 and are of polarity and potential sufficient to attract and focus incoming surface analyte ions. Preferably the potential applied toentry 203 and to electrode 206 are similar and that of 207 is higher.Additional electrodes conduit 201 further downstream from the entry. These last electrodes carry a controllable potential that is of the same polarity as is the incoming ion stream and serve to focus the ions into the central area of the conduit. - Reaction cloud 111 comprises a mixture of the gas issuing from the ion production means 14 and the ambient atmosphere, and contains sample ions formed by interaction of energetic ions from means 14 with
sample materials 15 in place onsurface 16. A stream ofgas 91, comprising reaction cloud 111, is drawn throughconduit 201 by action of pump 22 (FIG. 1 ), and the ion concentration in that gas stream is increased due to the attractive influence of the potential field created by the charge applied toinlet 203. - The gas exchange portion of
means 80 comprises a two-chamber conduit formed by apartition wall portion 85 that is disposed exterior to and generally parallel withconduit walls orifice 87 located between the chamber ends is arranged to allow gas flow between upper chamber 88 andlower chamber 89. A flow of ions in theambient sample atmosphere 91 is directed into the entry of the upper chamber 88. The ambient sample atmosphere with ions removed exhausts from the chamber 88 end at 92. Meanwhile, asecond gas stream 94, for example, suitably preconditioned dry air, is directed into the entry of thelower chamber 89.Gas stream 94 passes throughchamber 89 and the exitingflow 95 is then directed into the entry of ion detection means 20. The cross sectional area of chamber 88 relative tochamber 89 and the flow rate ofsample atmosphere 91 relative to the flow rate of thesecond gas stream 94 are adjusted such that there is a small andconstant bleed 97 of gas from thelower chamber 89 into the upper chamber 88 through theorifice 87. - A
first electrode 98 having the same polarity as the incoming ions insample stream 91 is located within chamber 88 above theorifice 87, while a secondsimilar electrode 99, having a polarity opposite to the incoming ions, is located withinchamber 89 below the orifice. As the ions insample stream 91approach electrode 98, they are repelled and are directed toward and throughorifice 87. At the same time, the ions are attracted towardelectrode 99, which tends to pull ions fromsample stream 91 through the orifice and intogas stream 94. There may also be provided one or more guiding or focusingelectrodes 211 located inchamber 89 downstream fromorifice 87 to shape or accelerate the ion stream. By adjusting the flow ofgas stream 94 to a level substantially less than the flow ofgas stream 91, a concomitant concentration of ions instream 94, to a level as high as ten fold of that ofsample stream 91, is achieved. In addition to ion concentration, there is achieved a fairly complete elimination of helium or argon from the gas stream that enterssensor 20 in those situations where either helium or argon is present in the reaction cloud 111. - As was set out previously, a
preferred ion detector 20 is a microfabricated differential mobility spectrometer that typically has a plate spacing on the order of half a millimeter. That small plate spacing allows use of much higher electric fields than are usual in other detector systems such as those employing ion mobility spectrometers; e.g. as high as about 35,000 V/cm compared to about 600 V/cm. Higher variable electric fields allow the changes in the mobility of ions as a function of field strength to be exploited to enhance selectivity and resolution. However, the maximum electric field is limited by the voltage at which arcing between the plates occurs with resultant destruction of the detector. Arc over occurs at a much lower voltage with helium or argon than with air. Consequently, removal of helium and argon from the sample gas stream that is analyzed allows for operation of the detector at higher field voltages thus further increasing the selectivity of the system. - A number of other synergistic advantages are obtained through the combination of the described ion production and concentration means with this particular detector. First of all, the ion production means of this invention does not use radioactive elements for ion creation and is therefore free of the regulatory burden imposed on devices employing radioactive sources. The corona discharge production of metastable helium atoms followed by the reaction of those metastable atoms with air to produce ions which in turn are used to ionize molecules of the sample is on the order of 1000 times more efficient than are those approaches that use the standard radioactive nickel or americium sources. Because the system of this invention creates far more ions of the sampled material than do conventional ion sources and because the preferred detector examines far more of the ions that are produced, fewer false positives or negatives result and superior resolution of targeted chemical ions from interferents is obtained.
- In another embodiment of this invention, both the ion source and the ion collection means and detector are operated in a pulsed cyclic mode. In this mode, ion production and collection can be seen as two half cycles, the first half cycle being diagrammed in
FIG. 9 and the second half cycle being diagrammed inFIG. 10 . Referring now toFIG. 9 a, agas stream 101 carrying negatively charged reactant ions issues from theoutlet 51 of theion production device 14 and is directed towardsurface 16 having asample material 15 deposited thereon. Stand off distance betweenoutlet 51 andsurface 16 may conveniently range from less than one inch to six inches or more, thus allowing a non-contact and non-destructive inspection of the surface for the presence of the sample material. -
Ion production device 14 is configured to produce reactant ions of predominately one charge; in this case it is producing negative ions. A negative potential is applied to anelectrode 106 that is located at the tip ofoutlet 51. That negative charge acts to accelerate the negative ions contained in the gas stream issuing fromoutlet 51 towardsurface 16. Asimilar electrode 108 is located at the tip of ion collection means and/ordetector inlet 109.Inlet 109 may comprise either the inlet to ion detection means 20, in which case electrode 77 ofFIG. 7 andelectrode 108 are the same, or it may comprise an inlet means 203 toion concentrator 80 ofFIG. 8 . The potential onelectrode 108 at this stage of the cycle is zero or ground potential. Also, the negative pressure at thedetector inlet 109 may be decreased during this time so as not to pull gas and ions fromstream 101 toward the detector inlet. - The next stage of the cycle is depicted in
FIG. 9 b.Electrode 106 remains at a negative potential andelectrode 108 remains at zero potential. A reaction cloud 111, typically comprising a mixture of air and helium and containing negatively charged surface sample ions, among other species has formed above the surface that is being examined. Thereafter, as is diagrammed inFIG. 9 c, the reactant ion production pulse has ended. A negative potential is maintained onelectrode 106 while the potential onelectrode 108 is changed from zero to positive and the negative pressure at the detector inlet is increased.Electrode 108 is shaped and charged to produce an electric field that has the effect of drawing the ions in reaction cloud 111 toward the detector inlet. As shown inFIG. 9 d, before the ion cloud reacheselectrode 108, its potential can be switched from positive to neutral so as to not destroy the oncoming negative ions by collision. Alternatively, the potential onelectrode 108 can be left on and the collisions of ions with walls avoided by focusing the ions within the ion collection means as shown inFIG. 8 . At the same time, the negative pressure at the ion inlet is increased to thereby capture much of the ion cloud and deliver it as a pulse to the ion detector. Optionally but preferably, the ion cloud pulse is delivered first toion concentrator 80 and then to the differential mobility spectrometer. - The second half cycle is the obverse of the first half cycle, and is diagrammed in the steps shown in
FIGS. 10 a through 10 d.Ion production device 14 is now configured to produce positive reactant ions, which are carried in thehelium stream 101 issuing fromoutlet 51. The potential applied to electrode 106 remains positive throughout the entire half cycle, first accelerating positive ions toward thesurface 16 and thereafter repelling the reaction cloud 111. Flow of thereactant ion stream 101 is ended after formation of the reaction cloud. The potential applied toelectrode 108 is briefly switched to negative (FIG. 10 c). The shape and charging ofelectrode 108 is sufficient to attract positive ions, including those formed from thesample material 15, towardinlet 109. At the same time, a negative pressure is applied toinlet 109, drawing the reaction cloud toward and into the inlet. The potential ofelectrode 108 can be then switched from negative to neutral (FIG. 10 d) before the ion cloud reaches the electrode so as to minimize destruction of the positive ions. Alternatively, the potential onelectrode 108 can be left on and the collisions of ions with walls avoided by focusing the ions within the ion collection means as shown inFIG. 8 . Thereafter, the reaction cloud is delivered as a pulse to the ion concentrator or detector. - Cycle length can be varied over a fairly large range as the time for completing a cycle depends upon a number of controllable factors. Those factors include standoff distance between the ion outlet and the sample surface, gas flow rate delivered by the ion production means, and the configuration of the gas exit orifice. Generally speaking, a cycle can be completed in as little as 0.5 seconds or extended to several seconds in length. It is usually advantageous to maintain cycle times as short as possible. Cycle time can be controlled by feedback from the differential mobility spectrometer. The timing of detection of certain reactant ions indicates the place in the cycle, allowing for automatic adjustment of the controls determining cycle time.
- Furthermore, it may be advantageous in certain situations to have a positive ion and a negative ion collection cycle for either or each of the positive or negative reactant ion production cycles. In this manner, information concerning both positive and negative surface sample ions produced in response to either positive or negative reactant ions can be obtained and used for identification purposes.
- The components making up the system of this invention may be and preferably are assembled in a manner that facilitates different modes of use.
FIG. 11 is a schematic diagram of one embodiment of this invention in which all of the system components are assembled as a fully portable, hand-helddetector 180 that contains its own helium supply. Asubassembly 183 that includes those components within the dashedline 182 defines a common platform that can be used for each of the different configurations of the system. This common platform includes air and helium valving and gas flow control means 184, reactant ion production means 14, sample ion collection, detection and identification means 20, and an operator interface andcontrol unit 186. - An on-
board helium supply 190, conveniently in the form of a disposable cartridge containing pressurized gas, provides an adequate supply for a limited number of analyses and thus is suitable for use by first responders, law enforcement and military personnel. Acomputer 192 together with its operating software controls the functioning of the system including helium and air flows and the operating parameters of thereactant ion source 14 that in turn depend upon whether the system is being operated in a continuous or in a cyclic mode. The computer also uses information from rangefinder 49 (standoff distance from the ion source outlet to the surface that is being investigated) and sensor information to control reactant ion production and surface sample ion collection to maximize both. The software carried incomputer 192 employs a number of different algorithms to distinguish between and to identify ions and charged molecular fragments that result from the impingement of reactant ions, inion stream 101, upon asurface 16 that has deposited thereon chemical compounds or other agents of interest or concern. - In a preferred embodiment, a number of different algorithms are carried in the computer, a different algorithm for each of different classes of materials. In this case,
algorithm 1 is specific to chemical warfare agents,algorithm 2 is specific for explosives,algorithm 3 is specific for drugs of both the prescription and illegal varieties, andalgorithm 4 is specific for toxic industrial chemicals and other toxic industrial materials. The system also requires apower source 195 that may include both batteries and a transformer-inverter for AC use. Readout means 198 is arranged to report the results of an analysis, and may be adapted to provide data either in visual form or as a printout. All of the system components reside within a case 199, which can be easily carried and maneuvered during use. - The system of
FIG. 11 may also be configured in another mode in which the helium supply tank is separated from the other system components with the helium being supplied from a larger tank carried separately by the system operator. For example, a tank as small as 21 inches in height and 3.5 inches in diameter and weighing on the order of ten pounds, can contain as much as 550 liters of helium. That would allow up to about 30 hours of continuous operation at a use rate of 300 ml/min. - A limited portable configuration may also be employed. In this mode of operation the common platform, as defined in
FIG. 11 , is assembled within a separate case that is tethered to a stationary base by means of a flexible cable for passing electrical signals and a flexible hose for supplying helium. This configuration provides mobile detection and surface interrogation capability within a fixed radius of a stationary point and avoids any weight or size limitations on the choice of a computer, its operation/detection software, power source and display/printer/data storage devices. It can also better accommodate the largest and most robust libraries of algorithms for distinguishing explosives, drugs, chemical warfare agents, and toxic industrial chemicals from interferents and innocuous substances. This configuration is especially advantageous for use at security and transportation checkpoints to monitor people, baggage, cargo, and material surfaces, as well as for the examination of baggage or incoming deliveries on conveyor belts, and for military, law enforcement, prison and industrial monitoring. The common platform, in whole or in part, and in conjunction with other parts of this configuration, can be used to examine items passing before it, whether such item be baggage or industrially produced items such as pharmaceuticals in order to determine the presence or absence of certain target chemicals in each different use. - Finally, the system can be deployed as a non-portable, bench top detector mode. This arrangement is particularly useful in those applications requiring high volume examination or scanning of field-collected samples, or in those instances in which a detailed scanning and examination of suspect objects is needed
- Other variations and modifications that are not specifically set out in the description herein will be apparent to those skilled in the art and the described invention is to be limited only by the scope of the following claims.
Claims (89)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/122,459 US7138626B1 (en) | 2005-05-05 | 2005-05-05 | Method and device for non-contact sampling and detection |
US11/580,876 US7429731B1 (en) | 2005-05-05 | 2006-10-16 | Method and device for non-contact sampling and detection |
US11/987,632 US7586092B1 (en) | 2005-05-05 | 2007-12-03 | Method and device for non-contact sampling and detection |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/122,459 US7138626B1 (en) | 2005-05-05 | 2005-05-05 | Method and device for non-contact sampling and detection |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/580,876 Continuation US7429731B1 (en) | 2005-05-05 | 2006-10-16 | Method and device for non-contact sampling and detection |
Publications (2)
Publication Number | Publication Date |
---|---|
US20060249671A1 true US20060249671A1 (en) | 2006-11-09 |
US7138626B1 US7138626B1 (en) | 2006-11-21 |
Family
ID=37393258
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/122,459 Active US7138626B1 (en) | 2005-05-05 | 2005-05-05 | Method and device for non-contact sampling and detection |
US11/580,876 Expired - Fee Related US7429731B1 (en) | 2005-05-05 | 2006-10-16 | Method and device for non-contact sampling and detection |
US11/987,632 Expired - Fee Related US7586092B1 (en) | 2005-05-05 | 2007-12-03 | Method and device for non-contact sampling and detection |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/580,876 Expired - Fee Related US7429731B1 (en) | 2005-05-05 | 2006-10-16 | Method and device for non-contact sampling and detection |
US11/987,632 Expired - Fee Related US7586092B1 (en) | 2005-05-05 | 2007-12-03 | Method and device for non-contact sampling and detection |
Country Status (1)
Country | Link |
---|---|
US (3) | US7138626B1 (en) |
Cited By (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20060243901A1 (en) * | 2003-04-25 | 2006-11-02 | Barket Dennis Jr | Instrumentation, articles of manufacture, and analysis methods |
US20070205362A1 (en) * | 2006-03-03 | 2007-09-06 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US20080067348A1 (en) * | 2006-05-26 | 2008-03-20 | Ionsense, Inc. | High resolution sampling system for use with surface ionization technology |
US20080078944A1 (en) * | 2006-09-07 | 2008-04-03 | Andreas Hieke | Computer controlled active feedback system for ldi/es ion source with electro-pneumatic superposition |
US20080087812A1 (en) * | 2006-10-13 | 2008-04-17 | Ionsense, Inc. | Sampling system for containment and transfer of ions into a spectroscopy system |
US20090090858A1 (en) * | 2006-03-03 | 2009-04-09 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US7576322B2 (en) * | 2005-11-08 | 2009-08-18 | Science Applications International Corporation | Non-contact detector system with plasma ion source |
US20090289183A1 (en) * | 2008-05-21 | 2009-11-26 | Zhiqiang Chen | Sample processing system and sample processing method for trace detector |
US20100044561A1 (en) * | 2006-07-13 | 2010-02-25 | Micromass Uk Limited | Apparatus comprising an ion mobility spectrometer |
US20100200746A1 (en) * | 2007-07-11 | 2010-08-12 | Excellims Corporation | Intelligently controlled spectrometer methods and apparatus |
WO2011022364A1 (en) * | 2009-08-17 | 2011-02-24 | Temple University Of The Commonwealth System Of Higher Education | Vaporization device and method for imaging mass spectrometry |
US20110042559A1 (en) * | 2009-08-18 | 2011-02-24 | Stefan Klepel | Substance identification using a series of ion mobility spectra |
WO2011075451A1 (en) * | 2009-12-18 | 2011-06-23 | Thermo Finnigan Llc | Pneumatically-assisted electrospray emitter array |
US7997119B2 (en) | 2006-04-18 | 2011-08-16 | Excellims Corporation | Chemical sampling and multi-function detection methods and apparatus |
US8008617B1 (en) | 2007-12-28 | 2011-08-30 | Science Applications International Corporation | Ion transfer device |
US20110238225A1 (en) * | 2010-03-24 | 2011-09-29 | Anubhav Tripathi | Method and system for automating sample preparation for microfluidic cryo tem |
CN102237249A (en) * | 2010-04-30 | 2011-11-09 | 安捷伦科技有限公司 | Input port for mass spectrometers that is adapted for use with ion sources that operate at atmospheric pressure |
US8071957B1 (en) | 2009-03-10 | 2011-12-06 | Science Applications International Corporation | Soft chemical ionization source |
US8123396B1 (en) | 2007-05-16 | 2012-02-28 | Science Applications International Corporation | Method and means for precision mixing |
US8207497B2 (en) | 2009-05-08 | 2012-06-26 | Ionsense, Inc. | Sampling of confined spaces |
US20120241607A1 (en) * | 2010-03-24 | 2012-09-27 | Arijit Bose | Microfluidic blotless cryo tem device and method |
US20130012795A1 (en) * | 2011-07-05 | 2013-01-10 | Collar Id Llc | Apparatus and methods for sensing a parameter with a restraint device |
US8440965B2 (en) | 2006-10-13 | 2013-05-14 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US8754365B2 (en) | 2011-02-05 | 2014-06-17 | Ionsense, Inc. | Apparatus and method for thermal assisted desorption ionization systems |
US20140245843A1 (en) * | 2011-10-04 | 2014-09-04 | Commissariat a l'energie atomic et aux energies alternatives | Device for Sampling Dust or Solid Particles in Particular for the Detection of Explosives |
US8901488B1 (en) | 2011-04-18 | 2014-12-02 | Ionsense, Inc. | Robust, rapid, secure sample manipulation before during and after ionization for a spectroscopy system |
US9337007B2 (en) | 2014-06-15 | 2016-05-10 | Ionsense, Inc. | Apparatus and method for generating chemical signatures using differential desorption |
US20170219526A1 (en) * | 2014-08-05 | 2017-08-03 | Dh Technologies Development Pte. Ltd. | Methods for Distinguishing Dioleinates of Aged and Non-Aged Olive Oil |
WO2017208026A1 (en) * | 2016-06-03 | 2017-12-07 | Micromass Uk Limited | Ambient ionisation spot measurement and validation |
EP3285059A1 (en) * | 2009-05-27 | 2018-02-21 | Micromass UK Limited | System and method for identification of biological tissues |
US10274404B1 (en) * | 2017-02-15 | 2019-04-30 | SpecTree LLC | Pulsed jet sampling of particles and vapors from substrates |
US10670561B2 (en) * | 2018-07-20 | 2020-06-02 | Battelle Memorial Institute | Device and system for selective ionization and analyte detection and method of using the same |
US10753829B2 (en) * | 2016-02-15 | 2020-08-25 | Spectree, Llc | Aerodynamic sampling of particles and vapors from surfaces for real-time analysis |
CN112534237A (en) * | 2018-06-21 | 2021-03-19 | 基美健有限公司 | System and method for analyzing pre-substrate processing |
US11043370B2 (en) | 2018-07-20 | 2021-06-22 | Battelle Memorial Institute | Device and system for selective ionization and analyte detection and method of using the same |
CN113295763A (en) * | 2021-06-03 | 2021-08-24 | 浙江师范大学 | Cross molecular beam detection device capable of eliminating interference of reactant background signals |
WO2022241196A1 (en) * | 2021-05-14 | 2022-11-17 | Shine Technologies, Llc | Ion production system with efficient ion collection |
Families Citing this family (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6949741B2 (en) * | 2003-04-04 | 2005-09-27 | Jeol Usa, Inc. | Atmospheric pressure ion source |
CA2570806A1 (en) | 2004-06-15 | 2006-01-05 | Griffin Analytical Technologies, Inc. | Analytical instruments, assemblies, and methods |
WO2006116564A2 (en) | 2005-04-25 | 2006-11-02 | Griffin Analytical Technologies, L.L.C. | Analytical instrumentation, appartuses, and methods |
US7138626B1 (en) * | 2005-05-05 | 2006-11-21 | Eai Corporation | Method and device for non-contact sampling and detection |
US20090050798A1 (en) * | 2005-06-03 | 2009-02-26 | Ohio University | Method for Sequencing Peptides and Proteins Using Metastable-Activated Dissociation Mass Spectrometry |
US7397560B2 (en) * | 2006-04-04 | 2008-07-08 | Agilent Technologies, Inc. | Surface contamination detection |
US7992424B1 (en) | 2006-09-14 | 2011-08-09 | Griffin Analytical Technologies, L.L.C. | Analytical instrumentation and sample analysis methods |
US7893408B2 (en) * | 2006-11-02 | 2011-02-22 | Indiana University Research And Technology Corporation | Methods and apparatus for ionization and desorption using a glow discharge |
US8232521B2 (en) * | 2007-02-02 | 2012-07-31 | Waters Technologies Corporation | Device and method for analyzing a sample |
TWI320395B (en) * | 2007-02-09 | 2010-02-11 | Primax Electronics Ltd | An automatic duplex document feeder with a function of releasing paper jam |
KR20150070427A (en) | 2007-12-05 | 2015-06-24 | 올테크 어소시에이츠, 인크. | Method and apparatus for analyzing samples and collecting sample fractions |
EP2335270A1 (en) * | 2008-10-03 | 2011-06-22 | National Research Council of Canada | Plasma-based direct sampling of molecules for mass spectrometric analysis |
AU2009325056A1 (en) | 2008-12-10 | 2011-06-30 | Alltech Associates Inc. | Chromatography systems and system components |
WO2011025564A1 (en) * | 2009-05-28 | 2011-03-03 | Georgia Tech Research Corporation | Direct atmospheric pressure sample analyzing system |
US8305582B2 (en) | 2009-09-01 | 2012-11-06 | Alltech Associates, Inc. | Methods and apparatus for analyzing samples and collecting sample fractions |
WO2013184320A1 (en) | 2012-06-06 | 2013-12-12 | Purdue Research Foundation | Ion focusing |
US9310308B2 (en) | 2012-12-07 | 2016-04-12 | Ldetek Inc. | Micro-plasma emission detector unit and method |
US9536725B2 (en) * | 2013-02-05 | 2017-01-03 | Clemson University | Means of introducing an analyte into liquid sampling atmospheric pressure glow discharge |
WO2015101821A1 (en) * | 2013-12-31 | 2015-07-09 | Dh Technologies Development Pte. Ltd. | Vacuum dms with high efficiency ion guides |
US10654056B1 (en) * | 2014-04-06 | 2020-05-19 | Clearist Inc. | Charge assisted spray deposition method and apparatus |
US9899196B1 (en) | 2016-01-12 | 2018-02-20 | Jeol Usa, Inc. | Dopant-assisted direct analysis in real time mass spectrometry |
US10126278B2 (en) | 2016-03-04 | 2018-11-13 | Ldetek Inc. | Thermal stress resistant micro-plasma emission detector unit |
US10636640B2 (en) | 2017-07-06 | 2020-04-28 | Ionsense, Inc. | Apparatus and method for chemical phase sampling analysis |
TWI672490B (en) | 2018-01-18 | 2019-09-21 | 財團法人工業技術研究院 | Calibrated particle analysis apparatus and method |
WO2019144228A1 (en) | 2018-01-23 | 2019-08-01 | Ldetek Inc. | Valve assembly for a gas chromatograph |
WO2019231859A1 (en) | 2018-06-01 | 2019-12-05 | Ionsense Inc. | Apparatus and method for reducing matrix effects when ionizing a sample |
JP2022553600A (en) | 2019-10-28 | 2022-12-26 | イオンセンス インコーポレイテッド | Pulsatile air real-time ionization |
US11913861B2 (en) | 2020-05-26 | 2024-02-27 | Bruker Scientific Llc | Electrostatic loading of powder samples for ionization |
Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US688132A (en) * | 1901-02-21 | 1901-12-03 | John Franklin Sims | Heating and ventilating apparatus. |
US4789783A (en) * | 1987-04-02 | 1988-12-06 | Cook Robert D | Discharge ionization detector |
US4974648A (en) * | 1989-02-27 | 1990-12-04 | Steyr-Daimler-Puch Ag | Implement for lopping felled trees |
US6225623B1 (en) * | 1996-02-02 | 2001-05-01 | Graseby Dynamics Limited | Corona discharge ion source for analytical instruments |
US6495823B1 (en) * | 1999-07-21 | 2002-12-17 | The Charles Stark Draper Laboratory, Inc. | Micromachined field asymmetric ion mobility filter and detection system |
US6512224B1 (en) * | 1999-07-21 | 2003-01-28 | The Charles Stark Draper Laboratory, Inc. | Longitudinal field driven field asymmetric ion mobility filter and detection system |
US6649907B2 (en) * | 2001-03-08 | 2003-11-18 | Wisconsin Alumni Research Foundation | Charge reduction electrospray ionization ion source |
US6727496B2 (en) * | 2001-08-14 | 2004-04-27 | Sionex Corporation | Pancake spectrometer |
US6744041B2 (en) * | 2000-06-09 | 2004-06-01 | Edward W Sheehan | Apparatus and method for focusing ions and charged particles at atmospheric pressure |
US6815668B2 (en) * | 1999-07-21 | 2004-11-09 | The Charles Stark Draper Laboratory, Inc. | Method and apparatus for chromatography-high field asymmetric waveform ion mobility spectrometry |
US6818889B1 (en) * | 2002-06-01 | 2004-11-16 | Edward W. Sheehan | Laminated lens for focusing ions from atmospheric pressure |
US20040245458A1 (en) * | 2003-06-07 | 2004-12-09 | Sheehan Edward W. | Ion enrichment aperture arrays |
US20050196871A1 (en) * | 2003-04-04 | 2005-09-08 | Jeol Usa, Inc. | Method for atmospheric pressure analyte ionization |
US6949741B2 (en) * | 2003-04-04 | 2005-09-27 | Jeol Usa, Inc. | Atmospheric pressure ion source |
Family Cites Families (96)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4000918A (en) | 1975-10-20 | 1977-01-04 | General Signal Corporation | Ferrule for liquid tight flexible metal conduit |
JPS5812982B2 (en) | 1976-10-01 | 1983-03-11 | 株式会社日立製作所 | chemical ionization ion source |
US4256335A (en) | 1977-05-23 | 1981-03-17 | Nielsen Jr Anker J | Positive locking terminal bushings for flexible tubing |
US4209696A (en) | 1977-09-21 | 1980-06-24 | Fite Wade L | Methods and apparatus for mass spectrometric analysis of constituents in liquids |
US4271357A (en) | 1978-05-26 | 1981-06-02 | Pye (Electronic Products) Limited | Trace vapor detection |
DE2855940C2 (en) | 1978-12-23 | 1980-08-21 | Bayer Ag, 5090 Leverkusen | Process for the separation of dichlorobenzene-containing isomer mixtures with the recovery of ortho-, meta- and / or para-dichlorobenzene |
US4318028A (en) | 1979-07-20 | 1982-03-02 | Phrasor Scientific, Inc. | Ion generator |
DE3125335A1 (en) | 1981-06-27 | 1983-01-13 | Alfred Prof. Dr. 4400 Münster Benninghoven | METHOD FOR ANALYZING GASES AND LIQUIDS |
JPS5935347A (en) | 1982-08-20 | 1984-02-27 | Masahiko Tsuchiya | Ion generator |
GB2127212B (en) | 1982-08-20 | 1987-08-12 | Tsuchiya Masahiko | Apparatus for producing sample ions |
US4542293A (en) | 1983-04-20 | 1985-09-17 | Yale University | Process and apparatus for changing the energy of charged particles contained in a gaseous medium |
US4531056A (en) | 1983-04-20 | 1985-07-23 | Yale University | Method and apparatus for the mass spectrometric analysis of solutions |
US4855595A (en) | 1986-07-03 | 1989-08-08 | Allied-Signal Inc. | Electric field control in ion mobility spectrometry |
US4976920A (en) | 1987-07-14 | 1990-12-11 | Adir Jacob | Process for dry sterilization of medical devices and materials |
US5171525A (en) | 1987-02-25 | 1992-12-15 | Adir Jacob | Process and apparatus for dry sterilization of medical devices and materials |
JP2753265B2 (en) | 1988-06-10 | 1998-05-18 | 株式会社日立製作所 | Plasma ionization mass spectrometer |
JP2543761B2 (en) | 1989-03-23 | 1996-10-16 | セイコー電子工業株式会社 | Inductively coupled plasma mass spectrometer |
US5168068A (en) | 1989-06-20 | 1992-12-01 | President And Fellows Of Harvard College | Adsorbent-type gas monitor |
US4977320A (en) | 1990-01-22 | 1990-12-11 | The Rockefeller University | Electrospray ionization mass spectrometer with new features |
NL9000606A (en) | 1990-03-16 | 1991-10-16 | Ericsson Radio Systems Bv | SYSTEM FOR THE TRANSMISSION OF ALARM SIGNALS. |
US5305015A (en) | 1990-08-16 | 1994-04-19 | Hewlett-Packard Company | Laser ablated nozzle member for inkjet printhead |
US5141532A (en) | 1990-09-28 | 1992-08-25 | The Regents Of The University Of Michigan | Thermal modulation inlet for gas chromatography system |
US5142143A (en) | 1990-10-31 | 1992-08-25 | Extrel Corporation | Method and apparatus for preconcentration for analysis purposes of trace constitutes in gases |
US5541519A (en) | 1991-02-28 | 1996-07-30 | Stearns; Stanley D. | Photoionization detector incorporating a dopant and carrier gas flow |
DE4130810C1 (en) | 1991-09-17 | 1992-12-03 | Bruker Saxonia Analytik Gmbh, O-7050 Leipzig, De | |
DE69224506T2 (en) | 1991-11-27 | 1998-10-01 | Hitachi Ltd | Electron beam device |
IL103963A (en) | 1991-12-03 | 1996-03-31 | Graseby Dynamics Ltd | Corona discharge ionization source |
US5192865A (en) | 1992-01-14 | 1993-03-09 | Cetac Technologies Inc. | Atmospheric pressure afterglow ionization system and method of use, for mass spectrometer sample analysis systems |
JP3238450B2 (en) | 1992-01-28 | 2001-12-17 | 株式会社日立製作所 | Mass spectrometer |
JPH05242858A (en) | 1992-02-27 | 1993-09-21 | Hitachi Ltd | Gas analyzing device |
US5306910A (en) | 1992-04-10 | 1994-04-26 | Millipore Corporation | Time modulated electrified spray apparatus and process |
US5338931A (en) | 1992-04-23 | 1994-08-16 | Environmental Technologies Group, Inc. | Photoionization ion mobility spectrometer |
JPH06310091A (en) | 1993-04-26 | 1994-11-04 | Hitachi Ltd | Atmospheric pressure ionization mass spectrometer |
US6537817B1 (en) | 1993-05-31 | 2003-03-25 | Packard Instrument Company | Piezoelectric-drop-on-demand technology |
JP3087548B2 (en) | 1993-12-09 | 2000-09-11 | 株式会社日立製作所 | Liquid chromatograph coupled mass spectrometer |
US5412208A (en) | 1994-01-13 | 1995-05-02 | Mds Health Group Limited | Ion spray with intersecting flow |
DE4408032A1 (en) | 1994-03-10 | 1995-09-14 | Bruker Franzen Analytik Gmbh | Process for the ionization of dissolved atoms or molecules from liquids by electrical spraying |
US5750988A (en) | 1994-07-11 | 1998-05-12 | Hewlett-Packard Company | Orthogonal ion sampling for APCI mass spectrometry |
DE19515271C2 (en) | 1995-04-26 | 1999-09-02 | Bruker Daltonik Gmbh | Device for the gas-guided transport of ions through a capillary tube |
US5625184A (en) | 1995-05-19 | 1997-04-29 | Perseptive Biosystems, Inc. | Time-of-flight mass spectrometry analysis of biomolecules |
DE19520276C2 (en) | 1995-06-02 | 1999-08-26 | Bruker Daltonik Gmbh | Device for introducing ions into a mass spectrometer |
US5559326A (en) | 1995-07-28 | 1996-09-24 | Hewlett-Packard Company | Self generating ion device for mass spectrometry of liquids |
US5587581A (en) | 1995-07-31 | 1996-12-24 | Environmental Technologies Group, Inc. | Method and an apparatus for an air sample analysis |
US6278111B1 (en) * | 1995-08-21 | 2001-08-21 | Waters Investments Limited | Electrospray for chemical analysis |
US5838002A (en) | 1996-08-21 | 1998-11-17 | Chem-Space Associates, Inc | Method and apparatus for improved electrospray analysis |
US5798146A (en) | 1995-09-14 | 1998-08-25 | Tri-Star Technologies | Surface charging to improve wettability |
GB9525507D0 (en) | 1995-12-14 | 1996-02-14 | Fisons Plc | Electrospray and atmospheric pressure chemical ionization mass spectrometer and ion source |
US5873523A (en) | 1996-02-29 | 1999-02-23 | Yale University | Electrospray employing corona-assisted cone-jet mode |
US5986259A (en) | 1996-04-23 | 1999-11-16 | Hitachi, Ltd. | Mass spectrometer |
US5945678A (en) | 1996-05-21 | 1999-08-31 | Hamamatsu Photonics K.K. | Ionizing analysis apparatus |
US5753910A (en) | 1996-07-12 | 1998-05-19 | Hewlett-Packard Company | Angled chamber seal for atmospheric pressure ionization mass spectrometry |
US5828062A (en) | 1997-03-03 | 1998-10-27 | Waters Investments Limited | Ionization electrospray apparatus for mass spectrometry |
US5892364A (en) | 1997-09-11 | 1999-04-06 | Monagle; Matthew | Trace constituent detection in inert gases |
CA2299439C (en) | 1997-09-12 | 2007-08-14 | Bruce A. Andrien | Multiple sample introduction mass spectrometry |
US6147345A (en) | 1997-10-07 | 2000-11-14 | Chem-Space Associates | Method and apparatus for increased electrospray ion production |
US6060705A (en) | 1997-12-10 | 2000-05-09 | Analytica Of Branford, Inc. | Electrospray and atmospheric pressure chemical ionization sources |
US6040575A (en) | 1998-01-23 | 2000-03-21 | Analytica Of Branford, Inc. | Mass spectrometry from surfaces |
US6124675A (en) | 1998-06-01 | 2000-09-26 | University Of Montreal | Metastable atom bombardment source |
US6107628A (en) | 1998-06-03 | 2000-08-22 | Battelle Memorial Institute | Method and apparatus for directing ions and other charged particles generated at near atmospheric pressures into a region under vacuum |
US5965884A (en) | 1998-06-04 | 1999-10-12 | The Regents Of The University Of California | Atmospheric pressure matrix assisted laser desorption |
GB2341270A (en) | 1998-09-02 | 2000-03-08 | Shimadzu Corp | Mass spectrometer having ion lens composed of plurality of virtual rods comprising plurality of electrodes |
AU6045400A (en) | 1999-02-25 | 2000-10-04 | Clemson University | Sampling and analysis of airborne particulate matter by glow discharge atomic emission and mass spectrometries |
US6239428B1 (en) | 1999-03-03 | 2001-05-29 | Massachusetts Institute Of Technology | Ion mobility spectrometers and methods |
US6223584B1 (en) | 1999-05-27 | 2001-05-01 | Rvm Scientific, Inc. | System and method for vapor constituents analysis |
US6359275B1 (en) | 1999-07-14 | 2002-03-19 | Agilent Technologies, Inc. | Dielectric conduit with end electrodes |
US6690004B2 (en) | 1999-07-21 | 2004-02-10 | The Charles Stark Draper Laboratory, Inc. | Method and apparatus for electrospray-augmented high field asymmetric ion mobility spectrometry |
US6455846B1 (en) | 1999-10-14 | 2002-09-24 | Battelle Memorial Institute | Sample inlet tube for ion source |
US6583407B1 (en) | 1999-10-29 | 2003-06-24 | Agilent Technologies, Inc. | Method and apparatus for selective ion delivery using ion polarity independent control |
US6486469B1 (en) | 1999-10-29 | 2002-11-26 | Agilent Technologies, Inc. | Dielectric capillary high pass ion filter |
US20030038236A1 (en) | 1999-10-29 | 2003-02-27 | Russ Charles W. | Atmospheric pressure ion source high pass ion filter |
CA2386832C (en) | 1999-10-29 | 2009-09-29 | Mds Inc. | Atmospheric pressure photoionization (appi): a new ionization method for liquid chromatography-mass spectrometry |
US6998605B1 (en) | 2000-05-25 | 2006-02-14 | Agilent Technologies, Inc. | Apparatus for delivering ions from a grounded electrospray assembly to a vacuum chamber |
US6465776B1 (en) | 2000-06-02 | 2002-10-15 | Board Of Regents, The University Of Texas System | Mass spectrometer apparatus for analyzing multiple fluid samples concurrently |
EP1314186A2 (en) | 2000-08-24 | 2003-05-28 | Newton Scientific, Inc. | Sample introduction interface for analytical processing |
US6683301B2 (en) | 2001-01-29 | 2004-01-27 | Analytica Of Branford, Inc. | Charged particle trapping in near-surface potential wells |
US6852969B2 (en) | 2001-01-29 | 2005-02-08 | Clemson University | Atmospheric pressure, glow discharge, optical emission source for the direct sampling of liquid media |
JP4627916B2 (en) | 2001-03-29 | 2011-02-09 | キヤノンアネルバ株式会社 | Ionizer |
DE10120336C2 (en) | 2001-04-26 | 2003-05-08 | Bruker Saxonia Analytik Gmbh | Ion mobility spectrometer with non-radioactive ion source |
US6583408B2 (en) | 2001-05-18 | 2003-06-24 | Battelle Memorial Institute | Ionization source utilizing a jet disturber in combination with an ion funnel and method of operation |
US6784424B1 (en) | 2001-05-26 | 2004-08-31 | Ross C Willoughby | Apparatus and method for focusing and selecting ions and charged particles at or near atmospheric pressure |
US7274015B2 (en) | 2001-08-08 | 2007-09-25 | Sionex Corporation | Capacitive discharge plasma ion source |
US20030099758A1 (en) | 2001-10-15 | 2003-05-29 | Book Sharon L. | Compositions and methods for producing phosphate salt mixtures and brine solutions to coagulate collagen |
US6610986B2 (en) | 2001-10-31 | 2003-08-26 | Ionfinity Llc | Soft ionization device and applications thereof |
WO2003041115A1 (en) | 2001-11-07 | 2003-05-15 | Hitachi High-Technologies Corporation | Mass spectrometer |
US7095019B1 (en) | 2003-05-30 | 2006-08-22 | Chem-Space Associates, Inc. | Remote reagent chemical ionization source |
US6888132B1 (en) | 2002-06-01 | 2005-05-03 | Edward W Sheehan | Remote reagent chemical ionization source |
US6949740B1 (en) | 2002-09-13 | 2005-09-27 | Edward William Sheehan | Laminated lens for introducing gas-phase ions into the vacuum systems of mass spectrometers |
US6822225B2 (en) | 2002-09-25 | 2004-11-23 | Ut-Battelle Llc | Pulsed discharge ionization source for miniature ion mobility spectrometers |
US6943347B1 (en) | 2002-10-18 | 2005-09-13 | Ross Clark Willoughby | Laminated tube for the transport of charged particles contained in a gaseous medium |
JP2004157057A (en) | 2002-11-08 | 2004-06-03 | Hitachi Ltd | Mass analyzing apparatus |
US6878930B1 (en) | 2003-02-24 | 2005-04-12 | Ross Clark Willoughby | Ion and charged particle source for production of thin films |
JP2004257873A (en) | 2003-02-26 | 2004-09-16 | Yamanashi Tlo:Kk | Method and apparatus for ionizing sample gas |
ITMI20041523A1 (en) | 2004-07-27 | 2004-10-27 | Getters Spa | IONIC MOBILITY SPECTROMETER INCLUDING A DISCHARGE IONIZING ELEMENT IN CROWN |
JP4492267B2 (en) | 2004-09-16 | 2010-06-30 | 株式会社日立製作所 | Mass spectrometer |
US7138626B1 (en) * | 2005-05-05 | 2006-11-21 | Eai Corporation | Method and device for non-contact sampling and detection |
US7196525B2 (en) | 2005-05-06 | 2007-03-27 | Sparkman O David | Sample imaging |
-
2005
- 2005-05-05 US US11/122,459 patent/US7138626B1/en active Active
-
2006
- 2006-10-16 US US11/580,876 patent/US7429731B1/en not_active Expired - Fee Related
-
2007
- 2007-12-03 US US11/987,632 patent/US7586092B1/en not_active Expired - Fee Related
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US688132A (en) * | 1901-02-21 | 1901-12-03 | John Franklin Sims | Heating and ventilating apparatus. |
US4789783A (en) * | 1987-04-02 | 1988-12-06 | Cook Robert D | Discharge ionization detector |
US4974648A (en) * | 1989-02-27 | 1990-12-04 | Steyr-Daimler-Puch Ag | Implement for lopping felled trees |
US6225623B1 (en) * | 1996-02-02 | 2001-05-01 | Graseby Dynamics Limited | Corona discharge ion source for analytical instruments |
US6815668B2 (en) * | 1999-07-21 | 2004-11-09 | The Charles Stark Draper Laboratory, Inc. | Method and apparatus for chromatography-high field asymmetric waveform ion mobility spectrometry |
US6512224B1 (en) * | 1999-07-21 | 2003-01-28 | The Charles Stark Draper Laboratory, Inc. | Longitudinal field driven field asymmetric ion mobility filter and detection system |
US6495823B1 (en) * | 1999-07-21 | 2002-12-17 | The Charles Stark Draper Laboratory, Inc. | Micromachined field asymmetric ion mobility filter and detection system |
US6744041B2 (en) * | 2000-06-09 | 2004-06-01 | Edward W Sheehan | Apparatus and method for focusing ions and charged particles at atmospheric pressure |
US6649907B2 (en) * | 2001-03-08 | 2003-11-18 | Wisconsin Alumni Research Foundation | Charge reduction electrospray ionization ion source |
US6727496B2 (en) * | 2001-08-14 | 2004-04-27 | Sionex Corporation | Pancake spectrometer |
US6818889B1 (en) * | 2002-06-01 | 2004-11-16 | Edward W. Sheehan | Laminated lens for focusing ions from atmospheric pressure |
US20050196871A1 (en) * | 2003-04-04 | 2005-09-08 | Jeol Usa, Inc. | Method for atmospheric pressure analyte ionization |
US6949741B2 (en) * | 2003-04-04 | 2005-09-27 | Jeol Usa, Inc. | Atmospheric pressure ion source |
US20040245458A1 (en) * | 2003-06-07 | 2004-12-09 | Sheehan Edward W. | Ion enrichment aperture arrays |
Cited By (83)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7462821B2 (en) * | 2003-04-25 | 2008-12-09 | Griffin Analytical Technologies, L.L.C. | Instrumentation, articles of manufacture, and analysis methods |
US20060243901A1 (en) * | 2003-04-25 | 2006-11-02 | Barket Dennis Jr | Instrumentation, articles of manufacture, and analysis methods |
US7576322B2 (en) * | 2005-11-08 | 2009-08-18 | Science Applications International Corporation | Non-contact detector system with plasma ion source |
US7700913B2 (en) | 2006-03-03 | 2010-04-20 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US20100102222A1 (en) * | 2006-03-03 | 2010-04-29 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US8026477B2 (en) | 2006-03-03 | 2011-09-27 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US20090090858A1 (en) * | 2006-03-03 | 2009-04-09 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US8217341B2 (en) | 2006-03-03 | 2012-07-10 | Ionsense | Sampling system for use with surface ionization spectroscopy |
US8497474B2 (en) | 2006-03-03 | 2013-07-30 | Ionsense Inc. | Sampling system for use with surface ionization spectroscopy |
US8525109B2 (en) | 2006-03-03 | 2013-09-03 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US20070205362A1 (en) * | 2006-03-03 | 2007-09-06 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US20110283776A1 (en) * | 2006-04-18 | 2011-11-24 | Excellims Corporation | Chemical sampling and multi-function detection methods and apparatus |
US8756975B2 (en) * | 2006-04-18 | 2014-06-24 | Excellims Corporation | Chemical sampling and multi-function detection methods and apparatus |
US7997119B2 (en) | 2006-04-18 | 2011-08-16 | Excellims Corporation | Chemical sampling and multi-function detection methods and apparatus |
US7705297B2 (en) | 2006-05-26 | 2010-04-27 | Ionsense, Inc. | Flexible open tube sampling system for use with surface ionization technology |
US8481922B2 (en) | 2006-05-26 | 2013-07-09 | Ionsense, Inc. | Membrane for holding samples for use with surface ionization technology |
US7714281B2 (en) | 2006-05-26 | 2010-05-11 | Ionsense, Inc. | Apparatus for holding solids for use with surface ionization technology |
US8421005B2 (en) | 2006-05-26 | 2013-04-16 | Ionsense, Inc. | Systems and methods for transfer of ions for analysis |
US7777181B2 (en) | 2006-05-26 | 2010-08-17 | Ionsense, Inc. | High resolution sampling system for use with surface ionization technology |
US20080067348A1 (en) * | 2006-05-26 | 2008-03-20 | Ionsense, Inc. | High resolution sampling system for use with surface ionization technology |
US10854437B2 (en) * | 2006-07-11 | 2020-12-01 | Excellims Corporation | Intelligently controlled spectrometer methods and apparatus |
US20190006160A1 (en) * | 2006-07-11 | 2019-01-03 | Excellims Corporation | Intelligently controlled spectrometer methods and apparatus |
US8076636B2 (en) * | 2006-07-13 | 2011-12-13 | Micromass Uk Ltd | Apparatus comprising an ion mobility spectrometer |
US8334502B2 (en) * | 2006-07-13 | 2012-12-18 | Micromass Uk Limited | Apparatus comprising an ion mobility spectrometer |
US20100044561A1 (en) * | 2006-07-13 | 2010-02-25 | Micromass Uk Limited | Apparatus comprising an ion mobility spectrometer |
US20120056084A1 (en) * | 2006-07-13 | 2012-03-08 | Micromass Uk Limited | Apparatus Comprising an Ion Mobility Spectrometer |
US20080078944A1 (en) * | 2006-09-07 | 2008-04-03 | Andreas Hieke | Computer controlled active feedback system for ldi/es ion source with electro-pneumatic superposition |
US8440965B2 (en) | 2006-10-13 | 2013-05-14 | Ionsense, Inc. | Sampling system for use with surface ionization spectroscopy |
US20080087812A1 (en) * | 2006-10-13 | 2008-04-17 | Ionsense, Inc. | Sampling system for containment and transfer of ions into a spectroscopy system |
US7928364B2 (en) | 2006-10-13 | 2011-04-19 | Ionsense, Inc. | Sampling system for containment and transfer of ions into a spectroscopy system |
US8123396B1 (en) | 2007-05-16 | 2012-02-28 | Science Applications International Corporation | Method and means for precision mixing |
US8308339B2 (en) | 2007-05-16 | 2012-11-13 | Science Applications International Corporation | Method and means for precision mixing |
US11417507B2 (en) * | 2007-07-11 | 2022-08-16 | Mark A Osgood | Intelligently controlled spectrometer methods and apparatus |
US9024255B2 (en) * | 2007-07-11 | 2015-05-05 | Excellims Corporation | Intelligently controlled spectrometer methods and apparatus |
US20100200746A1 (en) * | 2007-07-11 | 2010-08-12 | Excellims Corporation | Intelligently controlled spectrometer methods and apparatus |
US10049865B2 (en) * | 2007-07-11 | 2018-08-14 | Excellims Corporation | Intelligently controlled spectrometer methods and apparatus |
US20150303043A1 (en) * | 2007-07-11 | 2015-10-22 | Mark A. Osgood | Intelligently controlled spectrometer methods and apparatus |
US8008617B1 (en) | 2007-12-28 | 2011-08-30 | Science Applications International Corporation | Ion transfer device |
US20090289183A1 (en) * | 2008-05-21 | 2009-11-26 | Zhiqiang Chen | Sample processing system and sample processing method for trace detector |
US7947949B2 (en) | 2008-05-21 | 2011-05-24 | Nuctech Company Limited | Sample processing system and sample processing method for trace detector |
US8071957B1 (en) | 2009-03-10 | 2011-12-06 | Science Applications International Corporation | Soft chemical ionization source |
US8207497B2 (en) | 2009-05-08 | 2012-06-26 | Ionsense, Inc. | Sampling of confined spaces |
US8563945B2 (en) | 2009-05-08 | 2013-10-22 | Ionsense, Inc. | Sampling of confined spaces |
US8729496B2 (en) | 2009-05-08 | 2014-05-20 | Ionsense, Inc. | Sampling of confined spaces |
US9633827B2 (en) | 2009-05-08 | 2017-04-25 | Ionsense, Inc. | Apparatus and method for sampling of confined spaces |
US9390899B2 (en) | 2009-05-08 | 2016-07-12 | Ionsense, Inc. | Apparatus and method for sampling of confined spaces |
US8895916B2 (en) | 2009-05-08 | 2014-11-25 | Ionsense, Inc. | Apparatus and method for sampling of confined spaces |
EP3285059A1 (en) * | 2009-05-27 | 2018-02-21 | Micromass UK Limited | System and method for identification of biological tissues |
US10335123B2 (en) | 2009-05-27 | 2019-07-02 | Micromass Uk Limited | System and method for identification of biological tissues |
WO2011022364A1 (en) * | 2009-08-17 | 2011-02-24 | Temple University Of The Commonwealth System Of Higher Education | Vaporization device and method for imaging mass spectrometry |
US20110042559A1 (en) * | 2009-08-18 | 2011-02-24 | Stefan Klepel | Substance identification using a series of ion mobility spectra |
WO2011075451A1 (en) * | 2009-12-18 | 2011-06-23 | Thermo Finnigan Llc | Pneumatically-assisted electrospray emitter array |
US8242441B2 (en) | 2009-12-18 | 2012-08-14 | Thermo Finnigan Llc | Apparatus and methods for pneumatically-assisted electrospray emitter array |
US20110147576A1 (en) * | 2009-12-18 | 2011-06-23 | Wouters Eloy R | Apparatus and Methods for Pneumatically-Assisted Electrospray Emitter Array |
US9355813B2 (en) * | 2010-03-24 | 2016-05-31 | Brown University | Microfluidic blotless cryo TEM device and method |
US20110238225A1 (en) * | 2010-03-24 | 2011-09-29 | Anubhav Tripathi | Method and system for automating sample preparation for microfluidic cryo tem |
US20120241607A1 (en) * | 2010-03-24 | 2012-09-27 | Arijit Bose | Microfluidic blotless cryo tem device and method |
US9312095B2 (en) * | 2010-03-24 | 2016-04-12 | Brown University | Method and system for automating sample preparation for microfluidic cryo TEM |
CN102237249A (en) * | 2010-04-30 | 2011-11-09 | 安捷伦科技有限公司 | Input port for mass spectrometers that is adapted for use with ion sources that operate at atmospheric pressure |
US9224587B2 (en) | 2011-02-05 | 2015-12-29 | Ionsense, Inc. | Apparatus and method for thermal assisted desorption ionization systems |
US8963101B2 (en) | 2011-02-05 | 2015-02-24 | Ionsense, Inc. | Apparatus and method for thermal assisted desorption ionization systems |
US8822949B2 (en) | 2011-02-05 | 2014-09-02 | Ionsense Inc. | Apparatus and method for thermal assisted desorption ionization systems |
US9514923B2 (en) | 2011-02-05 | 2016-12-06 | Ionsense Inc. | Apparatus and method for thermal assisted desorption ionization systems |
US8754365B2 (en) | 2011-02-05 | 2014-06-17 | Ionsense, Inc. | Apparatus and method for thermal assisted desorption ionization systems |
US9105435B1 (en) | 2011-04-18 | 2015-08-11 | Ionsense Inc. | Robust, rapid, secure sample manipulation before during and after ionization for a spectroscopy system |
US8901488B1 (en) | 2011-04-18 | 2014-12-02 | Ionsense, Inc. | Robust, rapid, secure sample manipulation before during and after ionization for a spectroscopy system |
US20130012795A1 (en) * | 2011-07-05 | 2013-01-10 | Collar Id Llc | Apparatus and methods for sensing a parameter with a restraint device |
US9335236B2 (en) * | 2011-10-04 | 2016-05-10 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | Device for sampling dust or solid particles in particular for the detection of explosives |
US20140245843A1 (en) * | 2011-10-04 | 2014-09-04 | Commissariat a l'energie atomic et aux energies alternatives | Device for Sampling Dust or Solid Particles in Particular for the Detection of Explosives |
US9337007B2 (en) | 2014-06-15 | 2016-05-10 | Ionsense, Inc. | Apparatus and method for generating chemical signatures using differential desorption |
US9558926B2 (en) | 2014-06-15 | 2017-01-31 | Ionsense, Inc. | Apparatus and method for rapid chemical analysis using differential desorption |
US20170219526A1 (en) * | 2014-08-05 | 2017-08-03 | Dh Technologies Development Pte. Ltd. | Methods for Distinguishing Dioleinates of Aged and Non-Aged Olive Oil |
US9970900B2 (en) * | 2014-08-05 | 2018-05-15 | Dh Technologies Development Pte. Ltd. | Methods for distinguishing dioleinates of aged and non-aged olive oil |
US10753829B2 (en) * | 2016-02-15 | 2020-08-25 | Spectree, Llc | Aerodynamic sampling of particles and vapors from surfaces for real-time analysis |
WO2017208026A1 (en) * | 2016-06-03 | 2017-12-07 | Micromass Uk Limited | Ambient ionisation spot measurement and validation |
US11133169B2 (en) * | 2016-06-03 | 2021-09-28 | Micromass Uk Limited | Ambient ionisation spot measurement and validation |
CN109155230A (en) * | 2016-06-03 | 2019-01-04 | 英国质谱公司 | Measurement and verifying to open type ionization spot |
US10274404B1 (en) * | 2017-02-15 | 2019-04-30 | SpecTree LLC | Pulsed jet sampling of particles and vapors from substrates |
CN112534237A (en) * | 2018-06-21 | 2021-03-19 | 基美健有限公司 | System and method for analyzing pre-substrate processing |
US10670561B2 (en) * | 2018-07-20 | 2020-06-02 | Battelle Memorial Institute | Device and system for selective ionization and analyte detection and method of using the same |
US11043370B2 (en) | 2018-07-20 | 2021-06-22 | Battelle Memorial Institute | Device and system for selective ionization and analyte detection and method of using the same |
WO2022241196A1 (en) * | 2021-05-14 | 2022-11-17 | Shine Technologies, Llc | Ion production system with efficient ion collection |
CN113295763A (en) * | 2021-06-03 | 2021-08-24 | 浙江师范大学 | Cross molecular beam detection device capable of eliminating interference of reactant background signals |
Also Published As
Publication number | Publication date |
---|---|
US7138626B1 (en) | 2006-11-21 |
US7586092B1 (en) | 2009-09-08 |
US7429731B1 (en) | 2008-09-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7138626B1 (en) | Method and device for non-contact sampling and detection | |
WO2008054393A1 (en) | Method and device for non-contact sampling and detection | |
US7576322B2 (en) | Non-contact detector system with plasma ion source | |
US8592751B2 (en) | Methods and apparatus for enhanced ion based sample detection using selective pre-separation and amplification | |
US8173959B1 (en) | Real-time trace detection by high field and low field ion mobility and mass spectrometry | |
US7528367B2 (en) | Ion mobility spectrometer | |
US7714284B2 (en) | Methods and apparatus for enhanced sample identification based on combined analytical techniques | |
US4777363A (en) | Ion mobility spectrometer | |
WO2001022049A9 (en) | A novel ion-mobility based device using an oscillatory high-field ion separator with a multi-channel array charge collector | |
US7227134B2 (en) | Mobility based apparatus and methods using dispersion characteristics, sample fragmentation, and/or pressure control to improve analysis of a sample | |
CN103688164B (en) | Method and apparatus for ionizing gases using uv radiation and electrons and identifying said gases | |
US20080185512A1 (en) | Method and apparatus for enhanced ion mobility based sample analysis using various analyzer configurations | |
US20070272852A1 (en) | Differential mobility spectrometer analyzer and pre-filter apparatus, methods, and systems | |
US6822226B2 (en) | Corona ionization source | |
JP2005108578A (en) | Mass spectroscope | |
WO2000055600A2 (en) | Sampling and analysis of airborne particulate matter by glow discharge atomic emission and mass spectrometries | |
US7963146B2 (en) | Method and system for detecting vapors | |
US9744490B1 (en) | Trapped vortex particle-to-vapor converter | |
EP1580794B1 (en) | Mass spectrometric apparatus and ion source | |
US20100132561A1 (en) | Electrostatic charging and collection | |
CN203798779U (en) | Gas chromatograph and ion mobility spectrometer combined equipment | |
US6943343B2 (en) | Chemical agent detection apparatus and method | |
JP2004125576A (en) | Dangerous substance detection device and dangerous substance detection method | |
US7372020B2 (en) | Ion counter | |
US11621153B2 (en) | Mass spectrometry of surface contamination |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: EAI CORPORATION, MARYLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KARPETSKY, TIMOTHY P.;REEL/FRAME:016540/0585 Effective date: 20050421 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
CC | Certificate of correction | ||
AS | Assignment |
Owner name: SCIENCE APPLICATIONS INTERNATIONAL CORPORATION, CA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:EAI CORPORATION;REEL/FRAME:020353/0009 Effective date: 20071229 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
AS | Assignment |
Owner name: LEIDOS, INC., VIRGINIA Free format text: CHANGE OF NAME;ASSIGNOR:SCIENCE APPLICATIONS INTERNATIONAL CORPORATION;REEL/FRAME:032662/0606 Effective date: 20130927 |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
AS | Assignment |
Owner name: CITIBANK, N.A., DELAWARE Free format text: SECURITY INTEREST;ASSIGNOR:LEIDOS, INC.;REEL/FRAME:039809/0801 Effective date: 20160816 Owner name: CITIBANK, N.A., DELAWARE Free format text: SECURITY INTEREST;ASSIGNOR:LEIDOS, INC.;REEL/FRAME:039818/0272 Effective date: 20160816 |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553) Year of fee payment: 12 |
|
AS | Assignment |
Owner name: LEIDOS, INC., VIRGINIA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:CITIBANK, N.A., AS COLLATERAL AGENT;REEL/FRAME:051632/0742 Effective date: 20200117 Owner name: LEIDOS, INC., VIRGINIA Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:CITIBANK, N.A., AS COLLATERAL AGENT;REEL/FRAME:051632/0819 Effective date: 20200117 |