Vapor Detector Tubes and Detector Kit for Some Chemical Agents Used in Gas Warfare PAUL F. FENTON College of Medicine, University of Vermont, Burlington, Vermont
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URING an effort to assemble a convenient and compact chemical kit for field use by gas reconnaissance agents it was found that the available tests for chemical agents required a rather cumbersome array of miscellaueous equipment. To reduce the bulk of the detection equipment which had to be carried by the reconnaissance agent, efforts were directed toward the simplification of already existing chemical tests. The M-4 HS Vapor Detection Kit of the Chemical Warfare Service, U. S. Army, was taken as the outstanding example of compactness. With this in mind, other detector tubes were devised. They were prepared from glass tubing of 2-mm. internal diameter cut 3 to 4 cm. in length. Tubing of larger diameter may be used. The following types of tubes were prepared: (A) containing a 1- to 2-cm. column of silica gel' held in place by small tufts of absorbent cotton; (B) containing a 1to 2-cm. column of a 50-50 mixture of silica gel and 20mesh arsenic-free zinc. The lcit was equipped with the following reagents: (1) Sodium alcoholate: To 95 per cent ethyl alcohol add as much 8 per cent sodium amalgam as will react with it
in 24 hours. Filter. (2) Sulfanilamide reagent: Sulfanilamide. 0.2 gm.; N-(1naphthyll-ethylenediaminedihydrochloride, 0.2 gm.; concentrated hydrochloric acid, 20 cc. Filter. (3) Dimethylaniline. (4) Diphenylamine: 10 per cent solution in alcohol. (5) Dimethylaminobenzaldehyde: Pfanstiehl. 10 per cent solution in alcohol. (6) Mercuric bromide: Saturated water solution. (7) Hydrochloricacid: Concentrated. (8) Sadium or potassium hydroxide: I5 to20per cent. (9) Ilosvay reagent.P (10) Stannous chloride: 10 gm.in 25cc. of concentrated hydrochloric acid.
The principles of the reactions used here were by no means original but rather were taken from set.era1 source^.^^ The several color reactions, however, were carried out after the chemical agents had been adsorbed on the silica gel in the smalldetector tubes. 3p
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Kindly furnished by the Davison Chemical Corporation, Baltimore, Maryland. 4"Syllabus of Laboratory Experiments," War Department Civilian Protection School, Amherst C+ege. Amherst, MassaAND HICKEY, Chemical identification chusetts. Also. CLAPLIN of war gases." J. CHEM.E~uc.,20, 351-7 (1943). JACOBS, "War Gases," Interscience Publishers, Inc., New York. 1942. D0.1234. ' T~EADWELL AND HALL. "Analytical Chemistry." John Wiley and Sons, I n i , New York, 1937, Vol. I, p. 147.
The following procedures were used for the severaI cbemical agents : Chlorpicrin: This agent, adsorbed on silica gel of a type A tube, gave a deep orange color upon the addition of a drop of dimetbylaniline. The following coufirmatoty test was used: Sodium alcoholate was idded to another silica gel tube holding chlorpicrin, and the tube was heated over a burning match. The addition of the sulfanilamide reagent produced a bright purple color. The principle of this reaction was used by Jacobs3 in his modification of the Griess-Ilosvay reaction. This nitrite test may be carried out in a special detector tube containing silica gel, sulfanilamide powder, and N-(1-naphthy1)-ethylenediamine dihydrochloride (solid) separated from each other by small tufts of absorbent cotton. Contaminated air was aspirated through the tube. A drop or two of sodium alcoholate was added to the silica gel column which was then heated over a burning match. Several drops of concentrated hydrochloric acid were then added to the silica gel in such a way as to flow through the entire tube to the portion containing the sulfouamide and the substituted diamine. In the presence of chlorpicrin a bright pu4ple color developed. Phosgene: To a type A tube containing phosgene on silica gel were added successively a drop of diphenylamine and a drop of dimethylaminobenzaldehyde. An orange color developed. This was a modified use of Harrison's reagent2 which was found to be unstable. This same reaction may also be carried out in a special detector tube containing silica gel, diphenylamine, and dimethylaminobenzaldehyde separated from each other by absorbent cotton. Only small amounts of these reagents needed to be used. The contaminated air was aspirated through the tube, then several drops of alcohol were allowed to run through the entire length of the tube. An orange color developed. Still another form of this test has some merit. Strips of filter paper were impregnated with dimethylarninobenzaldehyde. When exposed to phosgene, a pale @en color developed which upon the addition of diphenylamine turned bright orange. Lksite: After aspiration through a type A tube, a drop of strong alkali and a drop or two of Ilosvay reagent were added and the tube was heated over a burning match. A red color developed. Blue or yellow coloration may result from side reactions and
must be considered negative, since they appear even in gave a slight reaction (pale yellow) with diphenylamine blank tests. and dimethylaminobenzaldehyde. When Lewisite was aspirated through a type B tube, Mustard: The kit was equipped with the HS Dea form of the Gutzeit reaction for arsenic became pos- tector Tubes of the M-4 kit as supplied through the sible. One of the cotton plugs was moistened with a O.C.D. Alkali and matches were already part of the drop of mercuric bromide, while through the other end equipment. of the tube concentrated hydrochloric acid was introIn addition to the detector tubes and reagent dropduced in sufficient quantity to react with the zinc ping bottles the kit also contained: several sheets of packed among the granules of silica gel. A brown stain vesicant detector paper (M-6) and vesicant 4etector developed .in the cotton plug moistened with mercuric crayon (M-7) developed by the Chemical Warfare bromide. Service; several sheets of vesicant detector paper deAnother way of testing for the arsenic in Lewisite veloped by the Warren Paper Company6; several was to aspirate the contaminated air through a type A strips of plain filter paper for kanying out some of the tube and convert the arsenic into sodium arsenite with above color reactions in the form of spot tests; a ruba drop of strong alkali and heat (burning match). This ber pressure bulb to aspirate contaminated air through was neutralized with a drop of concentrated acid. the detector tubes; tubes (made from damaged piUpon the addition of stannous chloride metallic arsenic pettes) charged with silica gel or charcoal for the collection of non-persistent agents for laboratory analysis; was formed (Bettendorf reaction4). The tests described here were tried on mustard, wide tubes (cutting in half the bulbs of damaged Lewisite, chlorpicrin, phosgene, benzene, acetone, ethyl pipettes) charged with absorbent cotton for the collecalcohol, and ammonia and were found to be specific tion of smokes; and a box of matches. The dimensions the complete kit were 4" X 4'/r" X 6'/eX. with the exception of the phosgene test, which was also of given by Lewisite. Furthermore the silica gel used here S. D. Warren Company, Boston, Massachusetts.
