DETERMINATION OF RESIDUES OF BANOL AND OTHER CARBAMATE PESTICIDES AFTER HYDROLYSIS AND CHLOROACETYLATION

An analytical method was developed to determine the residue of Banol (6-chloro-3,4-xylyl methylcarbamate) and 6-chloro-3,4-xylenol in Bermuda grass. After a liquid chromatographic cleanup and separation of 6-chloro-3,4-xylenol from Banol by extraction from methylene chloride with aqueous sodium hydroxide, the Banol was hydrolyzed in aqueous sodium hydroxide, the solution was shaken with chloroacetic anhydride in benzene, and an aliquot of the dried benzene phase was injected into a gas chromatograph. Recoveries of Banol in Bermuda grass at 3 and 0.1 p.p.m. were 86 and 95 %, respectively. For Banol, the minimum detectability was 0.04 p.p.m. for a 25-gram aliquot. The aliquot size was increased to 100 grams to improve detectability at this lower level. The use of this method to determine the residues of Banol in milk, apples, cucumbers, and tomatoes was examined, and the percentage recoveries of Banol, 6-chloro-3,4-xylenol, carbaryl, and 1-naphthol were investigated. The relative responses of electron-capture gas chromatography of Banol. carbaryl. and eight other methylcarbamates after hydrolysis and chloroacetylation were compared to heptachlor epoxide. © 1969, American Chemical Society. All rights reserved.