Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3645693 A
Publication typeGrant
Publication dateFeb 29, 1972
Filing dateNov 3, 1969
Priority dateNov 3, 1969
Publication numberUS 3645693 A, US 3645693A, US-A-3645693, US3645693 A, US3645693A
InventorsCrabtree Eleanor V, Poziomek Edward J
Original AssigneeUs Army
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Chemical detector
US 3645693 A
Electrophile compounds used as intermediates or pesticides can be detected by forming volatile derivatives of said compounds by treatment with N-alkylformamides producing isocyanide ions which contact an inert support medium, then treating said medium and its contents with a detector agent for said ions thus producing the color detector signal for said ions.
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Poziomek et al.

1 Feb. 29, 1.972

[54] CHEMICAL DETECTOR [72] Inventors: Edward J. Poziomek, Bel Air; Eleanor V.

Crabtree, Towson, both of Md.

[73] Assignee; The United States of America as represented by the Secretary of the Army 22 Filed: Nov. 3, 1969 21 AppLNos 373,107

[52] US. Cl. ..23/230 R, 252/408 [51] Int. Cl ..Go1n 21/12, GOln 31/22 [58] Field 01 Search ..23/230; 252/408; 260/465 A,

[ 5 6] References C ited UNITED STATES PATENTS 3,567,382 3/1971 Crabtree et al. ..23/230 3,405,160 10/1968 Eholzer et a1 ..260/46S A OTHER PUBLICATIONS l-lertler, W. R. et al., Journal of Organic Chemistry, Vol. 23, pp. 1221-2 1958) (P.0.S.L.).

Primary Examiner-Morris O. Wolk Assistant Examiner-Elliott A. Katz Attorneyllarry M. Saragovitz, Edward J. Kelly, Herbert Berl and Jacob Ziegler [57] ABSTRACT 6 Claims, No Drawings CHEMICAL DETECTOR DEDICATORY CLAUSE The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.

SPECIFICATION This invention is directed to the detection of electrophilic compounds which can be useful as intermediates in preparing other compounds or use in the agricultural field for detecting pesticides.

The object of this invention is the conversion of nonvolatile electrophiles to a more readily detectable volatile derivative of the electrophiles.

A general disadvantage of the former methods resides in that procedures require the determination to be carried out in liquid media, thus necessitating rather large masses of supporting equipment for solution detection and the manual handling of the sample containing the suspected compounds. The sample would have to be scraped or physically removed from the surface into aproper container for subsequent analysis in a solution procedure.

The advantage of our system lies in the minimum amount of handling the sample in view of the fact that the nonvolatile component is converted into a detectable volatile derivative. Thus the sample is no longer required to be removed from the surface for testing. The surface comprising the compound can be directly treated with the volatiling solution fonning a volatile component which is readily analyzed. Thus our system does not require physical handling of the sample, i.e., no scraping steps, and avoids any further contamination and can give greater weight to the validity of the results. In addition, inexperienced personnel can be employed since the usual chemical handling methods are no longer required.

A surface comprising about 0.1 to l.0p.g. of an electrophile is treated with about 10-100 1. of 1 normal N-loweralkylformamide and 100 .l. of a solvent, if desired, thus giving rise to the isocyanide ion in about 1 to 5 minutes. The isocyanide is adsorbed upon an inert support medium which is subsequently treated with a detector agent selected from the group consisting of benzidine and tetra base, producing a blue color detecting signal. If desired the inert support medium can be impregnated with the detector agent prior to exposure of the isocyanide ions, thus the support mediums blue color can be seen directly on the apparatus. The scheme, below, sets forth the general reaction of an electrophile with the aelimination giving rise to the corresponding isocyanide which is subsequently tested.

GENERAL SCHEME Wherein R or R, is an alkyl group, O-alkyl, S-alkyl or combinations thereof with the alkyl group containing from C to C carbon atoms.

X is oxygen or sulfur.

R, is hydrogen or an alkyl group from C to C, carbon atoms.

The more specific electrophiles are benzene sulfonyl chloride, toluene sulfonyl chloride, 0,0-dimethyl phosphorochloridothionate and diethylphosphorochloridate.

An interesting result from our studies is that all electrophiles do not give isocyanides in the presence of N-alkylformamides. Hoy et al., J. Org. Chem., 33, 4050 (1968) disclose the reaction between N-alkylformamide and electrophilic chemicals producing the imide. For example, a reaction N-butylformamide and acetyl chloride leading to N-(butyl)-N-formylacetamide.

As a result of our new method phosphorus-containing insecticide 0,0-dimethyl phosphorochloridothionate is readily detected in the field.

Tetra base reagent comprises mixing solutions of equal volumes of (a) 80-120 mg. of p,p -tetramethyldiaminodiphenylmethane and 400-600 mg. of salicylic acid in 100 ml. acetone and (b) 1.2-1.8 g. of cupric sulfate in 100 ml. of water. The preferred range is 100 mg. p,p'-tetramethyldiphenylmethane, 500 mg. salicylic acid and 1.5 g. cupric sulfate.

The benzidine reagent is mixed just prior to use, comprises equal volumes of (a) aqueous cupric acetate solution, 2.9453.43 g./ l. and (b) 675 ml. of benzidine acetate solution, saturated at room temperature, mixed with 525 ml. of water. The solutions (a) and (b) are best stored separately and in dark bottles. The preferred range for the aqueous cupric acetate is 2.86 g./l.

The use of silica gel tubes and the detecting apparatus for the isocyanide ion are well established in the open literature and may be employed according to the colorimetric method utilizing the described tetra base reagent or the benzidine reagent, Shepard, Anal. Chem., 19, 77, 1947; Williams et al.,

Anal. Chem., 34, 225, 1962; Crabtree et al., Talanta, 14, 857, 1967.

In general the silica gel tube is constructed as follows: A glass tube about 4 inches in length (3 mm. i.d.) containing an inert support medium, the untreated silica gel or treated silica gel, and then sealing off both ends of the glass tubing. The filling operations are those conventional in the art such as tamping the silica gel into the tube. Prior to use, each end of the filled tube is broken off and inserted in the various sampling apparatus.

When an unimpregnated silica gel detector tube is used, the isocyanide vapor is collected on the silica gel, the detector tube is removed from the apparatus, and the silica gel is moistened with a drop of either the benzidine or tetra base reagent. The appearance of a blue color is a positive test for the isocyanide.

The apparatus and the reagents we employed for the isocyanide detection are disclosed in copending patent application Ser. No. 723,487, filed 23 Apr. 1968. Now US. Pat. No. 3,567,382.

A solvent may be used, if desired, such as quinoline to facilitate the process, however, care must be taken that ethanol or dioxane are not employed since they interfere or inhibit the detection system.

EXAMPLE 1 a. A sample in a test tube comprising at least 0.2 g. of 0,0-

dimethyl phosphorochloridothionate, 100M. of N-methylfor- The latter tube is treated with about one drop (0.05 ml.) of the tetra base turning the silica gel blue indicating the presence of an isocyanide, thus demonstrating the original presence of an electrophile 0,0-dimethyl phosphorochloridothionate.

Higher concentrations of the phosphorus compounds are more readily detected and give rise to the isocyanide ion in a. short time.

h. The above procedure was repeated with the exception of utilizing the benzidine for the tetra base reagent.

EXAMPLE 2 The procedure according to Example I was followed with the exception of substituting other electrophiles of benzene sulfonyl chloride, toluene sulfonyl chloride or diethylphosphorochloridate for the phosphorochloridothionate giving rise to similar results, that is, a blue color with either the benzidine or tetra base reagent thus demonstrating the presence of electrophiles.

EXAMPLE 3 A surface comprising at least O.2 .g. of 0,0-

dimethylphosphorochloridothionate was treated with about EXAMPLE 4 The procedure according to Example 3 was followed with Y -Cl wherein Q is Q 0 E R X u P- or R or R is an alkyl group, O alkyl, S-alkyl or combinations thereof with the alkyl group containing from C l to C, carbon atoms.

X is oxygen or sulfur.

R is hydrogen or an alkyl group from C, to C; carbon atoms. in a reaction mixture comprising adding N-alkylformamide to produce volatile isocyanide ions, contacting an inert support medium with said isocyanide ions, treating said sup.- port medium and its contents with a detector agent for said isocyanide ions, producing the detector signal for said isocyanide ions and thereby indicating the presence of electrophiles.

2. The method according to claim 1, wherein Q is solution containing saturation benzidine acetate solution.

5. A method vaccording to claim 1, wherein the reaction mixture comprises a solvent.

6. A method according to claim 5, wherein the solvent is quinoline.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3405160 *Jun 21, 1965Oct 8, 1968Bayer AgXenyl-alkyl isonitriles
US3567382 *Apr 23, 1968Mar 2, 1971Us ArmyIsocyanide indicator
Non-Patent Citations
1 *Hertler, W. R. et al., Journal of Organic Chemistry, Vol. 23, pp. 1221 2 (1958) (P.O.S.L.).
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7662572Aug 25, 2006Feb 16, 2010Platypus Technologies, Llc.Compositions and liquid crystals
US7842499Aug 7, 2007Nov 30, 2010Platypus Technologies, LlcSubstrates, devices, and methods for cellular assays
US8178355Sep 15, 2009May 15, 2012Platypus Technologies, Llc.Detection of vapor phase compounds by changes in physical properties of a liquid crystal
US8268614Nov 10, 2004Sep 18, 2012Platypus Technologies, LlcMethod for assaying cell movement
US8512974Sep 14, 2012Aug 20, 2013Platypus Technologies, LlcMethod for assaying cell movement
US8988620Aug 31, 2009Mar 24, 2015Platypus Technologies, LlcLiquid crystal based analyte detection
US9103794Feb 8, 2012Aug 11, 2015Platypus Technologies LlcSubstrates, devices, and methods for quantitative liquid crystal assays
US9341576Apr 27, 2012May 17, 2016Platypus Technologies, LlcDetection of vapor phase compounds by changes in physical properties of a liquid crystal
US9518964Apr 14, 2011Dec 13, 2016Yoav EichenMethod for identifying electrophiles and nucleophiles in a sample
US20060141446 *Jan 30, 2006Jun 29, 2006Christopher MurphySubstrates, devices, and methods for cellular assays
US20080160539 *Aug 7, 2007Jul 3, 2008Platypus Technologies, LlcSubstrates, devices, and methods for cellular assays
US20090258430 *Feb 4, 2009Oct 15, 2009Technion Research & Development Foundation Ltd.Method for identifying electrophiles and nucleophiles in a sample
US20100093096 *Sep 15, 2009Apr 15, 2010Platypus Technologies, LlcDetection of vapor phase compounds by changes in physical properties of a liquid crystal
EP2085766A3 *Feb 3, 2009Sep 16, 2009Technion Research and Development Foundation, Ltd.Method for identifying electrophiles and nucleophiles in a sample
WO2006085971A2 *Jul 1, 2005Aug 17, 2006Platypus Technologies, LlcDetection of analytes
WO2006085971A3 *Jul 1, 2005Dec 7, 2006Platypus Technologies LlcDetection of analytes
U.S. Classification436/104, 436/120
International ClassificationG01N31/22, G01N31/00
Cooperative ClassificationG01N31/22, G01N31/00
European ClassificationG01N31/00, G01N31/22