WO1997007393A1

WO1997007393A1 - Apparatus for detection of soil and water contaminants by organic compounds

Info

Publication number: WO1997007393A1
Application number: PCT/US1996/013390
Authority: WO
Inventors: John Hanby
Original assignee: John Hanby
Priority date: 1995-08-15
Filing date: 1996-08-15
Publication date: 1997-02-27
Also published as: AU6850196A

Abstract

Apparatus and method for detection of organic contaminants in a sample of water or soil through extraction of the contaminants with an organic solvent followed by addition of a Friedel-Crafts Lewis acid catalyst to the extract to produce a reaction precipitate having a characteristic color indicative of the type and quantity of contaminant. The apparatus has a housing (1) with an opening to receive a test tube (2) containing the reaction precipitate into a chamber (6). Within the housing (1) are a light source (11), a fiber optic probe (8-10) and a CCD spectrometer (12) to illuminate and record the reflected light from the reaction precipitate in the test tube (2). The apparatus also has an external computer (14) for processing the recorded signal to determine the type and quantity of contaminants present in the sample.

Description

TITLE: APPARATUS FOR DETECTION OF SOIL AND

WATER CONTAMINANTS BY ORGANIC COM¬ POUNDS

CITATION TO PRIOR U.S. APPLICATION

This is a continuation application with respect to

U.S. Application Serial No. 08/515,261 , filed August 15,

1995 (15.08.95). Sole inventorship with respect to this Application and each of the foregoing lies with the present

Applicant.

FIELD OF THE INVENTION Applicant's invention relates to environmental analysis, and particularly to analysis of contamination of soil and water.

BACKGROUND OF THE INVENTION Quantitatively determining the levels of organic contamination in a sample of water or soil by visually comparing the color and intensity of a Friedel-Crafts [FC] product, produced by adding excessive amounts of a Lewis acid catalyst to an extract of the sample, was disclosed in Hanby, U.S. Patent No. 4,992,379 [hereinafter Hanby I]. Using the method of Hanby I, the FC product produced was then visually compared to a series of photographs of the FC products produced by standardized samples of various contaminants in known quantities to determine the quantity of contaminants present. Although the human eye is capable of extremely accurate comparisons, the method of Hanby I can only provide relatively good quantitative information. Qualitative (i.e. chemical identification) can only be obtained by having precise spectral data relating specific wavelengths to chemical structure.

In addition, the process disclosed in Hanby I specified the use of an alkyl halide and particularly carbon tetrachloride. This requirement was necessary in order to achieve low level (i.e. 1 ppm or less) contami¬ nation. For applications not requiring this level of sensitivity (i.e. applications in the 500 ppm or above range), Hanby II permits the use of non-halogenated solvents (e.g. heptane); thus, involving acylation type FC reactions as opposed to akylation reactions. Acylation reactions produces precipitates that are not necessarily visually differentiable whereas the spectrophotometer is capable of uniquely identifying and quantifying these precipitates.

The present invention [Hanby II] eliminates subjective factors that affected the reproducibility of results obtained using Hanby I by incorporating a light source, fiber optic cable, and a charge coupled device (CCD) spectrometer to measure the wavelength and intensity of the light reflected from the FC product. The electronic output from the spectrometer is then compared, using a digital computer, to the electronic signals or "fingerprints" produced by known samples of various contaminants. By using a computer to match the signals produced by the sample under investigation to the fingerprints, the reproducibility of results is greatly enhanced. In addition, by using spectral analysis, Hanby II is capable not only of determining quantitative levels of contaminants in samples but also of identifying the chemical composition of the sample. While certainly not the first use of spectrometry to identify environmental samples, it is the first use of visible spectrometry in combination with Friedel-Crafts reactions for the analysis of environmen¬ tal contamination.

SUMMARY OF THE INVENTION It is an object of this invention to provide a novel, useful and nonobvious portable device for inexpensively and accurately detecting organic contaminants in the soil or water. It is a further object of this invention to provide a novel, useful, and nonobvious device for detecting organic contaminants that eliminates subjective interpretations of the results.

It is a further object of this invention to provide a novel, useful, and nonobvious device for detecting organic contaminants that incorporates a CCD spectrometer to eliminate subjective interpretations that can result by visually comparing FC products to standardized samples.

It is a further object of this invention to provide a novel, useful, and nonobvious device for detecting organic contaminants that does not require potentially hazardous alkyl halides such as carbon tetrachloride.

BRIEF DESCRIPTION OF THE DRAWINGS Applicant's invention may be further understood from a descrip- tion of the accompanying drawings wherein, unless otherwise specified, like reference numbers are intended to depict like components in the various views.

Figure 1 is a diagram of the present invention. Figure 2 is a cross section of the fiber optic cable.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention comprises a housing 1 having an opening in its top surface. The opening is dimensioned to receive a test tube 2, test tube 2 containing the Friedel-Crafts [FC] product of an extracted sample of soil or water. The FC product is produced using the method disclosed in Hanby, U.S. Patent No. 4,992,379 incorporated by reference herein.

Module 5 resides within housing 1 and is adapted to receive test tube 2 and fiber optic probe 8 such that fiber optic probe 8 is located proximally to test tube 2. In the preferred embodiment, module 5 is made from an opaque, non-reflective, and black material that minimizes stray light interference. Module 5 includes a first chamber 6 that is dimensioned to receive test tube 2 through the opening in the top surface of housing 1. Module 5 also includes second chamber 7 that is dimensioned to receive fiber optic probe 8. Second chamber 7 extends through module 5 into first chamber 6 such that when test tube 2 is positioned within chamber 6, fiber optic probe 8 can be inserted into second chamber 7 to an adjustable position proximal to test tube 2.

Figure 2 depicts a cross section of the preferred embodiment of fiber optic probe 8. Probe 8 comprises a casing 15 that encloses six source fibers 9 and a single reflectance fiber 10. As shown in Figure 1 , source fibers 9 and reflectance fiber 10 are contained in probe 8. The source fibers 9 are connected to light source 11 and conduct light to test tube 2. Reflectance fiber 10 conducts the light reflected off of the FC precipitate in test tube 2 to CCD spectrometer 12. Returning to Figure 2, in the preferred embodiment, the source fibers 9 and the reflectance fiber 10 are each 200 μ.π, in diameter and are designed to promote extremely efficient and coherent transmission of the wavelengths critical to this analytical procedure (i.e. 450 nm to 575 nm). This portion of the visible spectrum is the most diagnostic region for this method.

In the preferred embodiment, a tungsten-halogen light source providing light energy across the visible spectrum, powered by a rechargeable battery (not shown) is used as light source 1 1. Light emitted from light source 1 1 is transmitted over source fibers 9 into probe 8 and reflected off the FC precipitate. The light reflected off of the FC precipitate is conducted over reflectance cable 10 into CCD spectrometer 12 where the optical signal is transduced into an analog electrical signal by spectrometer 12.

CCD Spectrometers are well known in the art. See, e.g.. Prytherch, U.S. Patent No. 5,235,402 and references cited therein. In the preferred embodiment, a commercially available CCD spectrometer that incorporates the single fiber optic as described is used. Such a device is available from Ocean Optics, Inc., of 1 104 Pinehurst Road, Dunedin, Florida 34698-5427; (813) 733-2447. In the preferred embodiment, the analog electrical signal output from CCD spectrometer 12 is routed, via ribbon cable 13, through an opening 3 in the side of housing 1 , to external computer 14 where the signal passes through a conventional analog-to-digital converter. Using appropriate software, the digital signals are then compared with stored signals produced from known samples. By matching the signals produced by the test sample to the stored images produced by the known samples, computer 14 can determine what quantities of contami¬ nants are present in the sample. Alternatively, the present invention could incorporate its own microprocessor, on-board ROM, and a simple LED display for internal analysis of the samples.

Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.

Claims

CLAIMS I claim:

1. A device for detection of organic contaminants in a sample of water or soil, wherein said sample is obtained by extracting said organic contaminants from said sample with an organic solvent to produce an extract, withdrawing said extract from said water sample or pouring said extract from said soil sample, and adding a Friedel-Crafts Lewis acid catalyst to said extract to produce a reaction precipitate having a characteristic color qualitatively and quantitatively indicative of said organic contaminant, comprising: a housing have a top side with an opening of sufficient diameter to receive a test tube containing said reaction precipitate; means for producing visible spectrum light, said means residing within said housing; first means for efficiently transmitting said light from said light producing means to a position proximal to the position occupied by said test tube when said test tube is insert¬ ed into said opening in said housing, such that said light is directed onto said reaction precipitate resulting in light being reflected from said reaction precipitate; means for transducing visible spectrum light into an analog electrical signal, said transducing means residing within said housing; and second means for efficiently transmitting said reflected light to said transducing means, whereby said reflected light is transduced by said transducing means into an analog electrical signal that uniquely identifies the Friedel-Crafts products of said sample extract.

2. The device of claim 1 , wherein said means for producing light comprises a tungsten halogen source powered by and adapted to receive a rechargeable battery.

3. The device of claim 1 , wherein said first transmission means comprised a plurality of fiber optic cables.

4. The device of claim 1 , wherein said second transmission means comprises a single fiber optic.

5. The device of claim 1 , wherein said transducing means comprises a charge coupled device (CCD) spectrometer.

6. The device of claim 1 , wherein, said means for producing light comprises a tungsten halogen source powered by and adapted to receive a recharge¬ able battery said first transmission means comprised a plurality of fiber optic cables; said second transmission means comprises a single fiber optic cable; and said transducing means comprises a charge coupled device (CCD) spectrometer.

7. The device of claim 1 wherein said housing has an opening in the side of said housing and further comprising a ribbon cable, connected to the output of said transducing means, for routing said analog electrical signal through said opening to external signal processing means.

8. In a process for detecting contaminants in a sample of water or soil wherein said sample is obtained by extracting said organic contaminants from said sample with an organic solvent to produce an extract, withdrawing said extract from said water sample or pouring said extract from said soil sample, and adding a Friedel-Crafts Lewis acid catalyst to said extract to produce a reaction precipitate having a characteristic color qualitatively and quantitatively indicative of said organic contaminant, wherein the improvement comprises; selecting means for generating visible spectrum light; generating visible spectrum light with said light generating means; transmitting, by efficient transmission means, said light to a location proximal to said reaction product such that said light is directed onto said reaction precipitate whereby light is reflected from said reaction precipitate; transmitting, by efficient transmission means, said reflected light to a means for transducing said reflected light into an analog electrical signal; transducing said reflected light into an analog electrical signal with said transducing means, whereby said analog electrical signal uniquely identifies the Friedel-Crafts products of said sample extract..

9. The process of claim 8, wherein said means for produc- ing light comprises a tungsten halogen source powered by and adapted to receive a rechargeable battery.

10. The process of claim 8, wherein said first transmission means comprised a plurality of fiber optic cables.

11. The process of claim 8, wherein said second transmission means comprises a single fiber optic cable.

12. The process of claim 8, wherein said transducing means comprises a charge coupled device (CCD) spectrometer.

13. The process of claim 8, wherein, said means for producing light comprises a tungsten halogen source powered by and adapted to receive a recharge¬ able battery; said first transmission means comprised a plurality of fiber optic cables; said second transmission means comprises a single fiber optic cable; and said transducing means comprises a charge coupled device (CCD) spectrometer.

14. The process of claim 8 wherein said housing has an opening in the side of said housing and further comprising a ribbon cable, connected to the output of said transducing means, for routing said analog electrical signal through said opening to external signal processing means.