US3474031A - Method and apparatus for automatic chromatography - Google Patents

Description

Oct. 21, 1969 N. J. BLONDEEL METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY Filed March 17. 1965 8 Sheets-Sheet 1 INVENTOR MCIw/aSJB/MM @ct. 21, 1969 N. J. BLONDEEL 3,474,031

METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY Filed March 17, 1965 8 Sheets-Sheet 2 Oct. 211, 1969 N. J. BLONDEEL 3,474,031

METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY Filed March l7, 1965 8 Sheets-Sheet 5 molasjfiiiilfi 0m. 21, R9 69 N. J. BLONDEEL METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY 8 Sheets-Sheet 4 Filed March 1,7, 196

FIG. 6 54x 5 INVE TOR elm/as JBlondeel ,M q QZLAK Get. 21, 1969 N. .1. BLONDEEL METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY Filed March 17, 196

8 Sheets-Sheet 5 Get 21, 1989 N. J. BLONDEEL METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY Filed March 17, 196E 8 Sheets-Sheet 6 l/YVE/YTOR Mic/101M]. Blended ct. 21, 1969 N. J. BLONDEEL 3,474,031

METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY Filed March 17, 1965 8 Sheets-Sheet 7 VE N TOR M01 awed 5/ 6 A777 67 Uct. 21, 1969 N. J. BLONDEEL 3,474,031

METHOD AND APPARATUS FOR AUTOMATIC CHROMATOGRAPHY Filed March 17, 1965 8 Sheets-Sheet Q INVENTOR Mc/wlas].Blonaleel Ci. 21tl-31 16 Claims ABSTRACT OF THE DISCLGSURE Method and apparatus for automatically performing manipulations in paper and thin layer chromatography including mechanism for maneuvering chromatographic sheets into and out of contact with solvent, mechanism for drying the sheets, and a monitor control for such mechanisms.

This invention relates to chromatographic apparatus and specifically deals with apparatus for automatically performing manipulations involved in adsorption and partition chromatography, mainly paper and thin layer chromatography.

Chromatography is an analytical method or technique of great value in analytical and microchemistry and particularly in biochemistry. A mixture of chemical substances can be separated, identified, and eventually measured by utilizing the differences in adsorption of each substance on adsorbent material such as filter paper, or a thin layer of adsorbent material such as silica gel on an inert base such as a glass plate. In paper chromatography the substances to be analyzed are applied to the chromatographic filter paper in spots at a so-called starting line or base line and a solvent is caused to continuously flow over the spots causing them to migrate from the starting line. The solvent carries the substances over a certain distance on the paper, with each distance difi'ering according to the partition coefficient of the substance, the property of the paper, the duration of solvent flow, the nature of the solvent, the surrounding temperature, etc. After the spots have migrated for a suitable distance from the starting line they are fixed in place on the paper by removing solvent such as by drying the paper and are then made visible by any suitable developing media such as ulraviolet light, radioactivity counting or of chromogenic chemicals such as a spray of Ninhydrin (1,2,3-indantrione hydrate) or a solution of phosphomolybdic acid. Migration of the spots by means of the solvent in the adsorbent material is often in a vertical direction, either descending or ascending.

The conventional apparatus for paper chromatography includes a chromatograph chamber or tank which provides an airtight zone which is first saturated with solvent vapor in the initial or stationary phase of the analysis. According to this invention such a tank is equipped with supporting brackets for suspending filter paper sheets or strips vertically in the tank. Troughs are provided either at the top or bottom of the tank to receive the ends of the filter paper sheets or strips to apply the solvent. The tanks provide airtight chambers and are kept at a constant temperature so that the solvent may travel up or down the paper at a constant rate. When the solvent reaches a certain distance from the starting point the papers are removed from the tank, placed in drying ovens, and developed with the chromogenic chemical, or other means.

Very often it is essential for accurate analysis that the travel of the solvent be stopped before it can run off the end of the sheet. Likewise it is important that the solvent be allowed to travel a sufficient distance from the starting point to fully separate the ingredients of the spots being analyzed.

nitcol States Patent 3,474,031 Patented Oct. 21, 1969 ice The solvent travel speed varies considerably and the operator must be in attendance at just the right time to insert or remove the sheets from the tank. This means that in a research biochemistry laboratory, for example, technicians must be available around the clock to perform the manipulative steps of inserting the solvent at the end of the stationary phase, stopping the solvent flow and drying the filter paper sheets. In analyzing amino acids, for example, a solvent composed of two parts of butyl alcohol, two parts of pyridine and one part of water is allowed to run through the filter paper for 12 hours or more Whereas in analyzing carbohydrates a solvent composed of 4 parts of amyl alcohol, 4 parts of pyridine and 1 part of water need only be run through the paper for several hours. Trial and error methods are necessary before standardized timing can be ascertained and all of this requires visual observation by the attending technician.

The present invention now eliminates the necessity for personal services of laboratory technicians to perform the various manipulations of starting and arresting solvent flow and drying chromatographs in paper and thin layer chromatography.

According to this invention there is provided apparatus that will faithfully handle strips or large sheets of chromatographic paper throughout the entire analytical procedure without damage or replacement. This apparatus automatically dips the paper sheets or thin layer plates into the solvent at the end of the stationary or saturating phase, removes the paper sheets or strips out of the solvent at any preselected time and then proceeds to automatically dry the papers or plates without removing them from the tanks or chambers.

The apparatus of this invention includes a monitoring device for a plurality of chromatanks and gives individual paper control in each chromatank. This apparatus is adapted for installation in standard chromatanks or cabinets and is expansible and contractible to handle wide sheets or narrow strips in both descending and ascending adsorption chromatography.

A feature of the invention is a provision of an electrode clamp applied to a chromatographic sheet or strip at a preselected level to remove the sheet or strip from the solvent when the solvent front line reaches this level. This is useful when the time schedule of a particular analysis is not yet known since the solvent run can be stopped at selected front line levels before the solvent runs olf of the end of the sheet.

Another feature of the invention is the capacity of the apparatus of this invention to accommodate both ascending and descending chromatography at the same time, e.g., for comparative analysis purposes.

Another feature of the invention resides in the provision of a plurality of individually actuated sheet or strip carriers in a single tank which will raise the sheet or strip out of contact with the solvent in the tank at a preselected time interval independently of the other sheets or strips in the tank hereby making possible selection of the same or different front lines for the analysis of the several sheets in the tank.

Another feature of the invention is the provision of an apparatus which will automatically initiate the drying operation in a chromatographic analysis upon the completion of a last adsorption run of a plurality of papers in a tank.

It is then an important object of this invention to provide chromatographic apparatus insertable in a standard chromatograph chamber and effective to automatically and selectively move each chromatographic strip or sheet or thin layer plate in the chamber into and out of contact with the solvent to be run through the sheet or strip or plate at the proper time.

Another object of the invention is to provide a chromatographic apparatus which will dip one end of the paper sheet or strip into the solvent at a preselected time after the stationary phase or saturation phase of the process.

Another object of this invention is to provide apparatus easily insertable in standard chromatanks or chambers for supporting adsorption paper sheets or strips in such a manner as to raise one end of the strip or sheet out of contact with a solvent at a preselected time.

A still further object of the invention is to provide a chromatographic apparatus which will automatically lift each adsorption paper individually out of contact with the solvent being run through the paper when the solvent reaches a predetermined level on the paper.

A still further object of the invention is to provide automatic paper chromatographic apparatus performing the functions heretofore requiring the services of laboratory technicians.

A still further object of this invention is to provide an apparatus which will monitor a plurality of chromatanks and cause the suspended filter paper in said tanks to be dipped in and raised out of contact with the solvent being run through the paper, at preselected time intervals.

A still further object of the invention is to provide an apparatus useful in both ascending and descending chromatography which will start and stop the solvent run through the adsorption material at the proper time without manual services of an attendant.

Another object of this invention is to provide an automatic chromatographic system.

Another object of this invention is to provide extensible and contractible apparatus for adsorption chromatography capable of handling a plurality of adsorption strips of variou sizes.

A still further object of this invention is to provide a clamp for suspending chromatographic paper which is easily applied to and removed from the paper without tearing or otherwise damaging the paper or interfering with the solvent run through the paper.

Other and further objects of this invention will become apparent to those skilled in this art from the following detailed description of the annexed sheets of drawings which, by way of preferred embodiments only, illustrate several examples of the invention.

On the drawings:

FIGURE 1 is a perspective view of a chromatank or chamber equipped with apparatus according to this invention set up for ascending chromatography and illustrating a monitoring device for controlling a plurality of chromatanks.

FIGURE 2 is a fragmentary perspective view of the apparatus of this invention set up for descending chromatography.

FIGURE 3 is a view similar to FIG. 2 illustrating the manner in which a tray for supporting the solvent troughs is removable and the manner in which the apparatus is extensible for accommodating narrow strips and wide sheets.

FIGURE 4 is a perspective view of an electrode clamp used in the apparatus of FIG. 1.

FIGURE 5 is a broken plan view of the cap or clamp for securing the adsorption paper on the support of the apparatus of this invention.

FIGURE 6 is a transverse cross sectional view along the line VIVI of FIG. 5

FIGURE 7 is a broken elevational view of a shaft or supporting member in the apparatus of this invention carrying the adsorption paper and coacting with the clamp cap of FIGS. 5 and 6.

FIGURE 8 is a transverse cross sectional view along the line VIIIVHI of FIG. 7.

FIGURE 9 is a broken elevational view of the cap and shaft of FIGS. 5 to 8 in assembled relation illustrating the manner in which the adsorption paper is supported and clamped thereon.

FIGURE 10 is a transverse sectional view along the line X-X of FIG. 9.

FIGURE 11 is a perspective view of a device for supporting the adsorption strips to receive the spots thereon and to be simultaneously clamped by the assembly of FIGS. 9 and 10 to carry the strips in equally aligned relation.

FIGURE 12 is a fragmentary front elevational view taken generally along the line XIIXII of FIG. 2, of the actuating apparatus for the adsorption paper supports.

FIGURE 13 is an exploded perspective view of one unit of the apparatus of FIG. 12.

FIGURE 14 is a somewhat diagrammatic elevational view illustrating the manner in which the apparatus of this invention is loaded for descending chromatography and the manner in which the adsorption paper is actuated by the apparatus.

FIGURE 15 is a fragmentary side view illustrating clearances necessary for rocking the bell crank support.

FIGURE 16 is a somewhat diagrammatic end elevational view of the apparatus loaded for ascending chromatography and illustrating the manner in which the adsorption paper is actuated by the apparatus.

FIGURE 17 is a somewhat diagrammatic perspective view illustrating the manner in which the actuating apparatus is easily accessible and is mounted on a single chassis under the hood.

FIGURE 18 is a wiring diagram of the chromatographic appaartus actuating mechanism.

FIGURE 19 is a wiring diagram of the electrical circuit of the monitoring device illustrated in FIG. 1.

As shown on the drawings:

As shown in FIG. 1 the reference numeral 10 designates generally a chromatank or cabinet having mounted therein the automatic apparatus 11 of this invention and controlled by a monitoring device 12 which can also have cable connections with a plurality of apparatus 11 in chromatanks or cabinets 10. The cabinet 10 is an upright generally rectangular metal or wood chest supported on legs 13 and having flat side walls 14 and end walls 15 each equipped with glass panels 16 to provide complete visual access to the entire interior of the chest. The chest has a flat solid bottom 17 and a removable top 18 also equipped with a glass panel 16. The front side wall 14 has a drawer opening therethrough just above the bottom 17 closed by a lid 19 whereby a tank or trough 20 may be inserted in the bottom of the chest to receive the solvent for ascending chromatography. The lid 19 has a handle 21 to remove it from the chest and latches 21a are provided to lock the lid to the chest.

One of the end walls 15 has an exhaust tube 23 extending therefrom and providing a louvered outlet 24 for exhausting the vapors from the interior of the chest. An exhaust fan 25 can be provided in the exhaust outlet 23 for pulling the vapors out of the chest and if desired heating means (not shown) can be provided in the chest to hasten the drying action.

The apparatus 11 of this invention is mounted in the upper portion of the chest and for this purpose a framework 26 is affixed to the side or end walls 14 or 15 of the chest at a level just sufficiently below the top 18 so that the apparatus will fit completely within the chest. The framework 26 as best shown in FIG. 2 includes a horizontal baseboard 27 providing a shelf extending across one end of the chest. Rails 28 extend from under this shelf along the front and rear side walls 14 of the chest up to the end wall 15 opposite the shelf carrying end wall. An upright rectangular board or end wall 29 is slidably mounted on these rails and includes a flat base strip 30 overlying the rails and extending forwardly from the bottom edge of the board 29 to coact with a corresponding strip 31 underlying the rails and suspended from the strip 30 by clamping bolts such as 32 whereby the end wall 29 is fixedly mounted at any selected position on the rails 28.

As shown in FIGS. 2 and 3 the board 29 overlies the rails 28, the base strip 30 extends forwardly from the bottom edge of the board 29 and also overlies the rails. The bottom strip 31 may take the form of two independent blocks 31 better shown in FIG. 3 suspended under the rail 28 by the bolt assembly 32 and adapted to be tightly clamped against the rail to lock the end wall assembly in fixed position at any selected portion of the rail. If desired and as also shown in FIG. 3 the front strip 30 can be reinforced with a rear strip 33 to add additional support to the board 29.

A rectangular metal hood or casing 34 is mounted on the shelf 27 and extends across substantially the entire width of the chest 10. The casing 34 has a vertical front face 35, a fiat horizontal top 36, a vertical back wall 37 (see FIG. 3) and flat vertical end walls 38. The front face or end wall parallels the end board 29 in spaced opposed relation.

A ledge or flange 39 on the hood 34 extends forwardly from the bottom edge of the shelf 29 between the rail 28 and a corresponding ledge or flange 40 extends forwardly from the bottom edge of the strip 30. These ledges 39 and 40 support an open bottom rectangular tray 41 having notched side walls 42 supporting V-shaped troughs 43 in spaced parallel relation across the tray. These troughs 43 hold the solvent for decending chromatography. As illustrated in FIG. 3 the tray 41 is removable from the assembly and can be used interchangeably with the tray 20 of FIG. 1 to convert the apparatus for use in both ascending and descending chromatography.

A plurality of driving axles 44 extend forwardly from the front wall 35 of the casing 34. The board 29 has idler axles 45 projecting forwardly therefrom in alignment with the axles 44. The forward ends of the axles 44 and 45 have slotted coupling ferrules 46 mounted thereon together with bell cranks 47 immediately adjacent the end board and the ferrule. The axles 45 are journaled for free rotation and axial movement in the board 29 and, as shown in FIG. 3, springs 48 are provided to urge the axles toward the casing 34.

The slotted ferrules 46 of the axles 44 and 45 are adapted to receive the ends of tie rods 49 (glass or stainless steel preferred) for drivingly connecting the driving axle 44 with the idler axle 45. These tie rods 49 are supplied in selected lengths to accommodate variable spacings of the end board 29 from the casing 34.

The bell cranks 47 as shown in FIGS. 15 and 16 have long arms 47a and short arms 47b in less than 90 relationship. The lengths and angular relationship of these arms are designed so that the long arms 47a will dip into the bottoms of the troughs 43 and so that neither arm will strike against the troughs when swung through the arcs shown in dotted lines in FIG. 15.

The ends of the long arms 47a have bayonet slots 50 therein while the ends of the arms 47b have circular holes 51 therethrough. The bayonet slots detachably carry the paper clips or clamps 52 for suspending the paper sheets or strips. The clamps 52 include a metal (stainless steel) channel strip 54 with stifi" but somewhat resilient side legs 55 and a rigid connecting web 56. A solid cylindrical metal rod 57 coacts with the channel strip 54. This rod 57 has a knurled or roughened circumference 58 intermediate its end, and grooves 59 are provided adjacent the end to fit into the bayonet slot 50 of the bell cranks 47 and provide journal ends for the rod. The grooved ends of the rod project beyond the ends of the channel strip 54 as shown in FIG. 9. The paper strip 53 has one end draped or looped over the knurled portion 58 of the rod 57 and the channel strip 54 is then snapped over the rod to clamp the looped end of the strip in fixed relation to the assembly. As shown in FIG. 10 the side legs 55 of the channel strip 54 are somewhat spread apart by the inserted rod 57 so that the paper 53 will be fixedly clamped over the rod 57.

As shown in FIG. 11 there is provided apparatus 60 for conveniently aligning the paper strip 53 for receiving spots 61 of material to be analyzed at the same starting line and for clamping or clipping the strip onto the clamp assembly 52 without permitting misalignment of the paper strips. Therefore, many paper strips can be clamped on quickly and in perfectly parallel relation to each other and at a perfect 90 angle with respect to the clip. The same apparatus, of course, can be made wider, to receive more than 2 strips or a big sheet of paper. This apparatus 60 includes a baseboard 63 having a flat top face 64 receiving the strip 53 thereover. Pins 65 project upwardly from the top 64 of the board near one end thereof. These pins are preferably arranged in pairs and the ends of the strip 53 preferably have pairs of apertures 62 therethrough to receive the pins. In this manner the strips are uniformly and fixedly aligned over the top 64 and for the spotting operation they can be covered with a glass plate 66 terminating just beyond the area to be spotted.

The board 63 has a groove 67 thereacross receiving an orificed tube 68 connected through a hose 69 with a source of drying air. The orifices of the tube 68 propel Warm air upwardly against the overlying strip 53 to rapidly dry the spot 61 thereon. The board 63 has a second groove 70 snugly receiving the channel strip 54 of the paper clip. The strip is mounted in an inverted position as shown and its legs 55 do not project above the top 64 of the board so that the strip 63 will span the open channel. To clamp the strips 53 to the clamp assembly 52 of this invention it is only necessary to press the rod 57 into the open top channel of the channel strip 54 thereby pushing the strips 53 ahead of the rod and forming the clamped assembly illustrated in FIGS. 9 and 10. Then the closed clip or clamp is merely lifted off of the board 63 and the strips are ready for mounting in the apparatus 11 of this invention by merely dropping the grooved ends 59 of the clips into the bayonet slot 50 of the bell cranks 47 as illustrated in FIGS. 15 and 16.

As shown in FIG. 14, for descending chromatography, to insure clearance of the strips 53 between the troughs 43 as well as free flow of chromogenic agent from the troughs, the strips 53 are draped over the tie rods 49 and over support rods or anti-syphon rods 71 carried in the holes 51 of the bell cranks 47. This provides for the raising and lowering of the strips 53 into and out of the troughs 43 without ever contacting that portion of the strip below the starting line of the spots 61 with any part of the trough or supporting tray. The starting line of the stops 61 is always sufficiently spaced from the clamped ends of the strips so that it will always be below the support 71 in all positions of the bell crank 47.

As shown in FIG. 16 for ascending chromatography the strip 53 is not draped over the tie rod 49 but extends directly downwardly from the clamp or clip 52 carried in the bayonet slot of the bell cranks 47. In the dotted line or lower position the strip is lowered sufficiently to dip into the bottom tank or trough 20 whereas in the solid line position the strip is raised sufficiently to be above the level of the solvent in the trough 20.

As shown in FIGS. 1 and 4 an electrode clip 72 is provided to trigger the apparatus 11 of this invention for moving the sheets 53 out of the solvent troughs Whenever the solvent reaches the level on the sheets at which the electrode is mounted. The electrode 72 has a pair of fingers 73 pivoted together intermediate their ends at 74 and having a spring 75 therebetween to urge jaw ends 76 thereof together. These jaw ends carry current conducting plates 77 each of which is connected to a separate wire 78 for closing a circuit between the wires whenever there is electrical current conduction between the plates. As illustrated in FIG. 1 when the plates 77 are on opposite sides of a dry sheet 53 current will not be conducted between the wires 78. However, when the paper is wet with the solvent to a level extending between the plates 77 the liquid agent will conduct current if the conductivity of the solvent is adequate, otherwire an electrolyte is added to the solvent thereby completing the circuit between the wires 73 and triggering the apparatus 11 to raise the sheet or strip out of the solvent tank.

As shown in FIGS. 12, 13 and 17 the actuating apparatus 11 mounted under the hood 34 on the shelf 27 includes vertical side plates a and 80!) providing an elongated chassis or frame for a plurality of driving units 81, one such unit being provided for each driving axle 44. If desired the plate 8% can serve to support the wiring for the components.

Each unit 81 is composed of a low voltage D.C. miniature motor 82 mounted on a bracket 83 carried between the plates 80. A speed reduction gear assembly consisting of a spur gear 84 fixed to the shaft of the motor 82, a large gear 85 meshed with the gear 84 and carried by a shaft 86 journaled in flanges 83a of adjacent bracket 83, a worm 87 driven by the gear 85 drives a gear 88 on a shaft 89 supported by a strap harness 90 between the plates 80 and in turn driving a spur gear 91 meshed with a large gear 92 carrying a smaller gear 93 meshed with and driving an arcuate segment 94 rocking the axle 44. An end bracket 83' with a flange 83a supports the outboard end of the end shaft 86. It will be understood that this provides a very high gear reduction between the shaft of the motor 82 and the axle 44 so that the axle will be rocked at a very slow rate. It should also be understood that any other suitable gear reduction arrangement could be used but the herein illustrated arrangement provides a very compact lightweight effectively acting gear train.

As best shown in FIG. 13, the strap bracket 90 between the chassis plate 80 coacts with draw bolts 95 to secure the chassis plates together and to separate the plates for receiving the components there'between. In addition this bracket 90 carries a bracket 96 supporting leaf spring switches 97 and 98 which, as shown in FIG. 12, are in the path of brackets 99 and 100 on opposite side edges of the gear segment 94. The arrangement is such that the motor will be stopped and its direction of rotation on the next cycle reversed whenever a bracket 99 or 100 engages its respective switch 97 or 98. Thus, the shaft 44 will first be rotated slowly in a direction to lower the bell crank arm 47a into either the upper trough 43 or the lower pan 2th and when the arm reaches the bottom of its stroke a bracket on the gear segment will contact the adjacent switch to stop the motor. Then when the motor again receives a starting signal its direction of rotation will be changed by a relay 158 and the axle will be rotated in the reverse direction to raise the bell crank arm 47a to its uppermost position moving the paper out of either the top trough 43 or the bottom pan 20. When the arm reaches its uppermost position the other bracket on the gear segment will contact the opposite switch to again stop the motor and reverse it for its next cycle.

The rocking movements of the arm are very slow so as not to interfere with the solvent run or to agitate the solvent.

The monitoring device 12 of FIG. 1 can be set to time the power input to the motors 82 of each drive unit 81 and the electrodes 72 can be provided to override the monitor timing when the solvent run reaches the level of the electrode to conduct current between the electrode plates. The monitor 12 as shown in FIG. 1 is connected to each apparatus 11 of this invention through cables 101.

As shown in FIGURE 19, the monitor 12 has a transformer 104 which has a primary winding 105 connected to a source of alternating current at terminals 106 and 107 which form a part of a plug 103. A main power switch 108 is provided between the terminal 1% and the primary winding, and a fuse 109 is provided between the terminal 107 and the primary winding 195. The secondary winding of the transformer 104 is connected to a bridge recti- O fier 112 which serves to deliver a low voltage DC curent, of approximately 4 volts, to the drive motors 82 or the chromatographic apparatus. The negative DC terminal of the bridge rectifier 112 is connected to a contactor 113 through a resistor 114 which is optionally provided should it be necessary to reduce the voltage delivered to the drive motors. The positive terminal of the bridge rectifier 112 is connected directly to a contactor 116. The contactors 113 and 116 are simultaneously actuated by a DC power delivery relay 117 which, in turn, is energized by the alternating current from terminals 106 and 107 in a manner to be described hereinbelow. A relay 117 has a first lead 118 connected to the terminal 106 and a second lead 119 connected to the terminal 107 through a plurality of parallel connected switches 12%, 121, 122 and 123, any one of which, when closed, will energize the relay 117.

The contactor 120 is preferably a push button switch which can be selectively actuated to clip all of the chromatographic sheets simultaneously into the solvent. The contactor 121, which is a time delay responsive device, is actuated by suitable cam means on a timing motor when the timing motor has finished timing the stationary phase of the chromatographic cycle. The contactor 122 is also a time delay responsive device which is initially ener gized at the end of the timing cycle of a second timer 125. The contactor 123 is preferably actuated by push button means 128 and serves as an optional manual control to selectively terminate the mobile phase of the chro matographic cycle. Therefore, should any one of the contactors 120123 be actuated closed, the relay 117 will be energized to actuate contactors 113 and 116 and apply DC power to the drive motors.

Connected in series with the timing motor 125 is a contactor 129 which is actuated closed when the timing motor is set for a predetermined time interval corresponding to the stationary phase of the chromatographic cycle. At the end of the timing interval, suitable cam means driven by the motor 125 will actuate the contactor 129 to the open position which, in turn, will remove the power from the timing motor.

Connected in series with the timing motor 126 is a contactor 131 which is actuated closed when the timing motor is set for a predetermined time interval corresponding to the direction of the mobile phase of the chromatographic cycle. In the present embodiment, the timing motor 126 must be set for a greater time interval than that of timer 125 to prevent the mobile phase timer 126 from inadvertently completing its timing cycle before the stationary phase timer 125 has completed its timing cycle; however, this is not to be construed in a limiting sense. The timing motor 125 may have additional switch means associated therewith which is actuated at the end of its timing cycle to initiate the timer 126 at the end of the stationary phase.

Also actuated by the imer 126 are contactors 132 and 133 which serve to energize a motor reversing relay and a fan motor respectively as will be discussed hereinbelow. Should it be desired to render the fan motor inoperative at all times, a switch 135, which is connected in series with the contactor 133, is placed in the open position. Since the contactors 121 and 122 are time delay responsive devices, and since the contactors 121 and 122 are momentarily actuated when the timing motors 125 and 126 are initially set to their predetermined time intervals, the power switch 108 should be maintained in the open position until after the timers 125 and 126 have been set.

The push button switch 128 has a second contactor 135 which is connected in parallel with the contactor 132 and serves to energize the motor reversing relay when the mobile phase of the chromatographic cycle is terminated manually.

A variable voltage dropping resistor 138 is connected between the negative DC terminal of the bridge rectifier 9 112 and circuit point D of a terminal strip 139 to change the operating characteristic of a transistor 163 in accordance with the type of solvent used.

Shown in FIG. 18 are a pair of drive motor systems 140, one of which is shown in detail by 140a. It will be understood that many drive motor systems can be connected in parallel to provide control for a multiplicity of chromatographic sheets. The circuitry of FIG. 18 is preferably located in the housing 34, FIG. 1, and is connected to the monitor 12 by means of the multi-conductor cable 181 which is connected between a terminal strip 142 and the terminal strip 139 of FIG. 19. The circuit points on the terminal strips 139 and 142 which are connected together by the cable 101 are indicated by corresponding letters A through I. That is, the circuit point A on the terminal strip 139 is connected to the circuit point A on the terminal strip 142 by means of a conductor in the cable 191.

As shown in FIG. 18, the drive motor 82 has a lead 145 connected to a contactor 146 and the terminal point 147. The contactor 146 serves as an up limit switch which is actuated by gear 94 thereby deenergizing the 'motor 82 after it has completely raised the chromatographic sheet from the solution. The other lead 148, of the motor 82, is connected to a contactor 150 and to a circuit point 151. The contactor 150 serves as a down limit switch which is actuated by the quadrant gear 94, FIG. 12, to deenergize the motor 82 after the chromatographic sheet has been dipped into the solution. The stationary contact of the down limit switch 150 is connected to a circuit point 153, while the stationary contact of the up limit switch 146 is connected to a circuit point 154.

A pair of contactors 156 and 157 are actuated simultaneously by a reversing relay 158. One lead from the reversing relay 158 is connected to the circuit point C, of terminal strip 142, through a line 159. The other lead of the relay 158 is connected to the terminal point H, of terminal strip 142, through a line 169 and a diode 161. The diode 161 serves as a blocking diode when the relay 158 and motor 82 are individually energized by the electrode clip 72. The cathode electrode of the diode 161 is connected to a collector electrode of a transistor 163 through an up limit switch 164. The up limit switch 164 is actuated by the quadrant gear 94 to deenergize the relay 158 upon completion of raising the particular chromatographic sheet from the solution. The emitter electrode of the transistor 163 is connected to circuit point G, of the terminal strip 142, through a line 166, while the base electrode of the transistor 162 is connected to the electrode clip 72. To deliver DC power to the motor 82 to raise the chromatographic sheet from the solution, a contactor 157 is actuated simultaneously with the contactors 156 and 157 by the motor reversing relay 158.

As the ions of the solution pass through the chromatographic sheet secured between the electrode 72, the conductivity between the electrode 72 will gradually increase. This effect is similar to a variable resistor connected in series with the base electrode of transistor 163, as represented by the variable resistor 169. Therefore, as the ion concentration increases between the electrode 72, so also will the current flow increase through the transistor 163 to energize the reversing relay 158. The diode 161 in each of the motor control circuits 140 serves to prevent energization of the relay 158 in each of the control systems 141) until each electrode clip 72 has sensed the proper ion concentration from the solution to render the transistor 163 conductive.

A ventilating fan has one lead thereof connected to a circuit point I of the terminal strip 142, while the other lead of the ventilating fan 25 is connected to a terminal point I through a plurality of serially connected switches represented by 171. The switch 171 is actually a series of switches each connected to a respective motor drive system 140. Therefore, the fan motor 25 will be energized when all of the chromatographic sheets are raised from the solution. Main switch 108 will then stop the fan at the end of the procedure.

The sequence of electrical operation of the chromatographic apparatus shown in FIG. 1 is best illustrated by reference to FIGS. 18 and 19. At the beginning of the cycle, the timer is set to a predetermined time as desired for the duration of the stationary phase of the chromatographic cycle. The timer 126 is then set to a predetermined time interval as desired for the mobile phase of the chromatographic cycle. It should be noted, that the time interval of the timer 126 is equal to the sum of the stationary phase and the mobile phase intervals. After the timers have been set, the main power switch 108 is closed thereby energizing the timer motors 125 and 126.

Before the start of the chromatographic sequence of the stationary phase one or more of the paper strips or paper sheets 53 is hung in the cabinet 10 by means of the paper clips 52, as shown in FIG. 1. The top 18 is preferably closed during the stationary phase to allow the solution in the trough 20 to evaporate and saturate the inside of the cabinet 10 with a vapor solution. The paper sheets 53 will then absorb the vapor solution and become somewhat saturated. The stationary phase of the chromatographic cycle may extend from zero to 24 hours depending on the timer 125.

At the end of the stationary phase, the timer 125 will have finished its timing interval and deactuate the contactor 129, thereby removing power from the timing motor. Also, at the end of the stationary phase, the time delay responsive contactor 121 is actuated and will remain actuated for approximately 30 seconds. During the 30 seconds, the relay 117 is energized which, in turn, will actuate the contactors 113 and 116 to deliver DC power to the circuit points E and F of the terminal strips 139 and 142. This action will cause the motor 82 to be energized and drive the axle 44 thereby lowering the top edge of the sheet 53 into a trough containing the solution, as shown in FIG. 16. As each of the paper sheets is dipped in the solution, the down limit switch is actuated open by the quadrant gear 94 to remove power from the respective drive motor. All of the sheets 53 are dipped in the solution within the 30 second time delay of contactor 121. The contactor 121 is then opened to deenergize the relay 117 and remove DC power from the circuit points E and F.

As mentioned hereinabove, the timing motor 126 is provided with a greater time interval than that of the timing motor 125. When the sheets 53 are dipped into the solution, the mobile phase of the chromatographic cycle is begun.

As shown in FIG. 14, the solution in the trough 43 is absorbed by the top portion 53a of the sheet 53 and travels therefrom to a somewhat downward portion 53b and into the body of the sheet 53 in a descending fashion or, as shown in FIG. 16, from the bottom of the paper to the top in ascending fashion. During the automatic operation of the chromatographic apparatus, the timer 126 will determine the mobile phase interval. However, the mobile phase interval can be terminated manually by depressing the push button switch 129. Also, the mobile phase interval can be terminated for each individual sheet 53 by means of the electrode clip 72, as mentioned hereinabove.

Upon completion of the mobile phase during any one of the above mentioned modes of operation, the relays 158 and 117 will be energized thereby applying power to the motor 82. This action will cause the motor 82 to run in the opposite direction as previously mentioned and raise the portion 53a, of the sheet 53, from the solution, as shown in FIG. 14 in case descending chromatography is used.

Upon completion of raising all of the portions 53a. of the sheets 53, the fan motor 25 may be energized to evacuate the vaporized solution from the tank 10. The switch 135 is placed in the open condition should it be desired not to energize the fan motor 25 at the end of the complete mobile phase.

It will be understood that the housing 34 can be rendered fireproof and/ or explosive proof by providing suitable ceiling means for each of the axles extending therefrom, and of the bottom.

OPERATION From the above descriptions it will be understood that the chromatographic strips are conveniently prepared on the apparatus of FIG. 11. These strips have a pair of holes through one end thereof for receiving the alignment pins 65. The strips 53 overlie the top face 64 of the baseboard 63 which can be small or wide in spaced parallel relation and can be conveniently covered with a plate 66 to hold them fiatwise on the face 64. The strips will span grooves 67 and 70 provided in the board 63 and spots 61 of the material to be analyzed are deposited on the strips over the grooves 67. These spots are quickly dried by an air blast from the orificed tube 68 in the groove 67. The groove 70 receives the channel 54 of the paper clip or clamp and after the spots 61 are dried the knurled rod 52 of the clamp is pressed into the channel carrying the strips therewith and locking them in looped relation over the clamp as illustrated in FIGS. 9 and 10.

The strips mounted in the clamp 52, are then removed from the board 63 and the grooved ends 59 of the clamp are deposited in the bayonet slot ends of the bell cranks 47 of the apparatus 11 of this invention mounted in the top of the chromatank or chest of FIG. 1.

If the apparatus is to be used for ascending chromatography the strips are draped on the bell cranks 47 as illustrated in FIG. 16 to depend directly downwardly from the clamps 52 into the tray or pan 20 in the bottom of the chest.

If the apparatus is to be used for descending chromatography before the strips are mounted on the bell cranks the hinged front door or lid 22 of the chest is opened to receive the trough supporting tray 41 which is slidably supported on the ledges 39 and 40 of the apparatus as best illustrated in FIG. 2. The tray 41 carries a series of V-shaped troughs which are filled with solvent at the start of the chromatographic procedure in spaced parallel relation with the space therebetween being ample to freely receive the strips or sheets without contacting the same. If desired a solvent storage reservoir inside or outside the tank, with magnetic valve system controlled by the monitor, can be used, in case one wants to fill the troughs automatically at the end of the stationary phase (circuit not shown).

The apparatus 11 is expansible and contractible to accommodate sheets or strips of widely varying width and for this purpose a slidable end wall 29 is provided to carry idler axles in variably spaced relation from the driving axles which project from the front face of the housing 34. Tie rods 49 of predetermined length connect the driving axles 4'4 with the driven axles 45 so that the rocker arms at both ends of the clamps will be driven at the same rate.

For descending chromatography and to avoid a sharp angle in the papers, the short arms 47b of the bell cranks 47 carry rods 51 and the sheets are draped over the tie rods 49 and after dipping in the solution over rods 51 as shown in FIG. 14. This also insures maintenance of the paper strips in the space between the troughs completely out of contact with the troughs.

The monitor 12 is set to provide a predetermined waiting period (stationary phase) before it actuates the apparatus in the casing 34 and each driving axle is driven by its own separate motor to lower the bell cranks thereby moving the sheets or strips into contact with either the upper troughs or the bottom pan of solvent. After a predetermined time period as set by the monitor or after the solvent has reached the electrode 72 the motors are again actuated to raise the paper out of contact with the solvent and the exhaust system is actuated to dry the sheets, until the main power switch 118 is opened. The motors of the timers are shut off by means of their own contactors 142 and 146, once they have reached the 0 time.

At the end of the procedure, the clamp 52, with the strips or paper sheets mounted upon, is used for further transport into a drying oven, in case more intensive drying is needed, or for the development of the separated substances in spraying chamber or dipping troughs, containing the chromogenic material, or UV. light sources. etc., thus preventing tearing, frequently encountered in the standard methods.

The automatic apparatus of this invention is easily mounted in existing chromatographic equipment and is effective to replace many manual operations now requiring the services of technicians.

Although various minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent granted hereon all such embodiments as reasonably and properly come within the scope of my contribution to the art.

I claim as my invention:

1. Chromatographic apparatus adapted to be mounted in the upper portion of a cabinet, troughs in said cabinet, solvent in said troughs, comprising a unit having a plurality of driving axles at one end thereof, an end member shiftable toward and away from said driving axles, a plurality of idler axles journaled in said end member and aligned with the driving axles, tie rods detachably connecting the driving and idler axles, bell cranks on all of said axles. said bell cranks having long arms with bayonet slots in the ends thereof and short arms in angled relation to the long arms and having apertures in the ends thereof, rods spanning the space between the idler axles and the driving axles having grooved ends seated in the bayonet slots of the bell cranks, channel strips disposed around the rods, chromatographic paper clamped to said rods by said channel strips, additional rods spanning the space between the idler axles and driving axles having ends received in the apertures of the short arms of the bell cranks, said additional rods receiving said paper thereover and depending therefrom, means for reversely rotating the driven axles to raise and lower the long arms of the bell cranks for dipping the paper into the solvent in the troughs and for raising the paper out of contact with said solvent, adjustable monitoring means controlling the driving of said driving axles so that the paper will automatically be dipped into and raised out of contact with the solvent at the proper time, means for drying the interior of said cabinet, and means energizing said drying means when the paper is raised out of contact with the solvent.

2. Chromatographic apparatus which comprises a unit having a fixed driving part and an adjustable wall part movable toward and away from the driving part to vary the distance therebetween, aligned raising and lowering means on said parts, paper supports spanning the space between said parts and detachably carried by said aligned raising and lowering means, means on said driving part for actuating said raising and lowering means, chromatographic paper carried by said supports, trough means having solvent therein receiving said paper when said raising and lowering means are lowered, and a monitoring control for the actuating means to determine the time cycle for operating the actuating means to raise and lower said raising and lowering means for dipping the sheets in the solvent carried by said trough means and for removing the sheets from said solvent.

3. Chromatographic apparatus which comprises a tank, solvent in the tank, a frame mounted in the upper portion of the tank, said frame including a horizontal shelf, a pair of horizontal rails, and a vertical end wall slidably mounted on the rails for movement toward and away from said shelf to vary the span therebetween, means for clamping said end wall on the rails, a housing on said shelf, driving mechanism in said housing having a plurality of axles projecting from the housing toward said end wall, idler axles journaled in the end wall for free rotation and endwise movement, springs urging the idler axles toward the driving axles, tie rods of selected length detachably connecting the driving axles with the idler axles, arms carried by the driving axles and the idler axles, clamps removable supported by said arms, chromatographic sheets carried by said clamps and positioned to be moved into and out of contact with the solvent in said tank, means for raising and lowering said arms to move said sheets into and out of contact with said solvent in the tank, and timing mechanism controlling the driving mechanism to control the dipping of the sheets into said solvent and the removing of sheets from the solvent.

4. Chromatographic apparatus for mounting in the upper part of a chromatographic cabinet which comprises a framework, a plurality of spaced troughs spanning said framework, mechanism carried by said framework for suspending chromatograph paper strips in the spaces between the troughs and for selectively dipping the ends of said strips into the troughs, said mechanism being shi-ftably mounted on said framework for movement from a first position dipping the ends of strips carried thereby into the troughs to a second position lifting said ends out of the troughs and means driving said mechanism between said first and second positions.

5. Chromatographic apparatus which comprises a cabinet, trough means in said cabinet, solvent in said trough means, means for suspending a chromatographic sheet in said cabinet, a chromatographic sheet suspended by said means, mechanism in said cabinet for raising and lowering said sheet into and out of solvent in said trough means, an electrode clamped on said sheet having electrical contacts on opposite sides of the sheet, an electric motor for driving said raising and lowering mechanism, an electric power circuit including said contacts and said motor closed by solvent between the contacts for energizing said motor to move the sheet out of the solvent, and timing mechanism for stopping said motor so that solvent traveling through said chromatographic sheet will automatically cause the sheet to be moved out of contact with the solvent when the solvent level in the sheet reaches the electrode.

6. Chromatographic apparatus which comprises a tank, solvent in said tank, and an electric motor in said tank, a gear reduction train driven by said motor, a gear segment driven by said train, electrical contacts opened and closed by the gear segment at opposite ends of the travel of the segment, an axle driven by the gear segment, an arm driven by the axle, a sheet supporting clip carried by the arm, an electrical circuit including said motor and a power source energized under control of the electrical contacts for driving said motor to raise and lower the arm and clip carried thereby for raising and lowering a sheet carried by the clip into and out of contact with solvent in the tank, and monitoring means controlling the time cycle of operation of said electric motor to provide a proper solvent run in the sheet.

7. An expansible and contractible automatic apparatus for chromatography which comprises a fixed shelf, driving means carried by said shelf having a plurality of horizontal driving axles projecting from the shelf, an end wall movable toward and away from said shelf, idler axles journaled in said end wall aligned with said horizontal driving axles, arms carried by said driving axles and idler axles, rods journaled at their ends to said driving axles and idler axles respectively, a tray slidably mounted beneath said shelf and end wall, troughs carried by said tray, and control mechanism for the driving means effective to cause the driving means to selectively rotate said driving axles in opposite directions to rotate the arms and rods for raising and lowering said arms at predetermined periods so that chromatographic sheets carried by said rods will be raised and lowered into said troughs at predetermined periods.

8. Chromatographic apparatus which comprises means defining a closed chamber, solvent in the chamber, means in said chamber for suspending chromatographic paper strips in the chamber, paper strips suspended from said means for suspending paper strips, means for raising and lowering said means for suspending paper strips to move the paper strips into and out of contact with said solvent, means for drying the interior of said chamber, and means energizing said drying means when said means for suspending the paper strips is in raised position and said paper strips are out of contact with said solvent.

9. Chromatagraphic apparatus which comprises a plurality of tanks, solvent in said tanks, suspension means for suspending paper strips in each of said tanks, means for raising and lowering said suspension means to move the paper strips suspended thereby into and out of contact with the solvent in the tanks, and monitoring means controlling said raising and lowering means to actuate the same at desired time intervals so that a plurality of chromatograph analyses can be performed.

10. Chromatographic apparatus which comprises a chest providing a closed chamber, suspension means in the top of said chest for suspending paper chromatographic strips in the chest, trough means in said chest containing solvent, means for lowering said suspension means to dip paper strips carried by the suspension means into solvent in said trough means, means for raising said suspension means to lift paper strips carried thereby out of the solvent in said trough means, means for exhausting vapors from the closed chamber, control mechanism for said means for raising and lowering said suspension means, control mechanism for actuating said means for exhausting vapors from the chest, and timing means for said control mechanisms to actuate said means for raising the suspension means for lifting strips carried thereby out of contact with solvent after predetermined time intervals and to energize said exhausting means to dry the strips in the chest.

11. Chromatographic apparatus which comprises a tank, solvent in the tank, suspension means in said tank carrying a chromatograph sheet for selective dipping into the solvent in the tank, an electrode clamped on said sheet having contacts engaging opposite faces of the sheet, means for raising and lowering said suspension means to move the sheet suspended thereby into and out of contact with solvent in the tank, a circuit including said electrode and a power source closed by solvent in the sheet between said contacts, and drive means in said circuit energized when the circuit is closed for driving said raising and lowering means to raise the sheet out of contact with the solvent so that the sheet will be automatically lifted out of contact with the solvent when the solvent runs through the sheet to the level of the electrode.

12. Apparatus for automatically performing adsorption chromatography which comprises a cabinet defining an enclosed chamber, a solvent container is said chamber, paper suspension means in said cabinet, means for raising and lowering said paper suspension means to move a paper strip suspended therefrom into and out of contact with solvent in the container, a motor for driving said raising and lowering means, means for drying paper suspended from said suspension means in said chamber, and a monitor control for said motor and drying means effective to automatically provide a time period to saturate the cabinet with solvent vapor, then actuate said motor to drive said means for raising and lowering said suspension means to dip the paper into the solvent for a predetermined period, to then reverse said motor to drive said means for raising and lowering to raise the suspension means to lift the paper from the solvent after 15 said predetermined period, and to then actuate the drying means for drying the paper.

13. The method of conducting a chromatographic analysis which comprises spotting a strip of chromatographic paper with material to be analyzed, suspending said strip in a cabinet containing a receptacle having electrolytic solvent therein, clamping an electrode on the strip having electrical contasts on opposite faces of the strip in spaced relation from the solvent in the receptable and from the spot on the strip to provide a desired length of solvent run in the strip from the spot, closing the cabinet, allowing the cabinet to be saturated with solvent vapor from said receptacle, lowering the strip to position an end thereof in the solvent in the receptacle, allowing the solvent to be adsorbed in the strip by capillary action until it reaches the electrode, closing an electrical circuit through the electrode with said electrolytic solvent, energizing a motor in the closed electrical circuit, driving the suspensions means with said motor to raise the strip out of the solvent, and drying the strip in the cabinet.

14. The method of conducting a chromatographic analysis which comprises spotting a strip of chromatographic paper with material to be analyzed, suspending the spotted strip, dipping an end of the strip in an electrolytic solvent adapted to 11111 through the spot and strip, closing an electrical power circuit with solvent in the strip at a selected level on the strip, energizing a motor from the closed electrical circuit, and driving a strip raising mechanism with the motor to lift the strip out of the solvent for stopping the solvent run in the strip.

15. Chromatographic apparatus which comprises a unit including a fixed part and an adjustable part movable toward and away from the fixed part, chromatographic paper supports carried between said parts, driving means in the fixed part for raising and lowering the supports, and monitoring means controlling the driving means to actuate the same at selected intervals in a chromatographic analysis.

16. The method of automatically performing adsorption chromatographic analyses which comprises placing a spot of material to be analyzed on a strip of chromatographic paper, suspending the spotted strip in a cabinet containing a solvent, positioning the suspended strip in the cabinet out of contact with the solvent, closing the cabinet with the suspended strip therein, allowing a first predetermined time period to elapse sufficient to permit the closed cabinet with the suspended strip therein to become saturated with solvent vapor, automatically upon elapse of said first time period shifting the suspended strip in the closed cabinet to dip an end of the strip into the solvent, allowing a second predetermined time period to elapse sufficient for the solvent to run through the spot on the strip to a front line level on the strip satisfactory for the analysis, automatically upon elapse of said second time period shifting said suspended strip in the cabinet to remove the strip from the solvent, automatically upon said shifting of the strip to remove the strip from the solvent exhausting vapors from the closed cabinet and drying said strip for a third predetermined time period, and automatically terminating said vapor exhausting and drying step upon termination of said third predetermined time period.

References Cited UNITED STATES PATENTS 2,875,144 2/ 1959 Karler. 3,046,779 7/ 1962. Coleman. 3,114,692 12/ 1963 MacDonell. 3,237,380 3/ 1966 Barrett 55-67 3,240,340' 3/1966 Hayes. 3,265,214 8/1966 Brodsky. 3,341,017 9/1967 Powell. 3,342,333 9/1967 Geiss et a1.

FOREIGN PATENTS 893,648 4/ 1962 Great Britain.

OTHER REFERENCES B. H. Davies, Saturation Chamber, J. Chromatog, vol. 10, 1963, pp. 518-521.

Chromatography Catalog, Scharr and Co., Catalog AC-56, March 1956, pp. 9-11.

REUBEN FRIEDMAN, Primary Examiner C. M. DITLOW, Assistant Examiner US. 01. X.R. 210-138, 143, 19s

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,474,031 October 21, 1969 Nicholas J. Blondeel It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 58, "hereby" should read thereby Colun 4, line 29, "appaartus" should read apparatus Column 6, li 50, "stops" should read spots Column 7, line 2, "otherwire should read otherwise Column 8, line 55, "imer" should read timer Column 10, line '62, "129" should read 128 Column 14, line 60, "is" should read in Column 15, lin 7, "contasts" should read contacts line 8, "resceptable" should read receptacle line 19, "suspensions" should read suspension Signed and sealed this 26th day of May 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. JR-

Attesting Officer Commissioner of Patents

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