Abstract
Technical grade samples of fenitrothion were analyzed by high pressure liquid chromatography (HPLC) on a reverse phase LiChrosorb RP-8 column, using 3 solvent systems and a UV detector set at 269 nm. All commercial samples analyzed contained >94% fenitrothion; in addition, 9 contaminants were identified and quantitated. Bisfenitrothion was the major contaminant, with average amounts of 2.46% from one manufacturer and 1.17% from another. The second most abundant toxicant was S-methyl fenitrothion, which was present at an average level of 0.71% in one source but only 0.16% in the other. The amount of fenitrooxon was 0.046% or less in samples from 2 manufacturers. Other contaminants quantitated include the 2 demethyl fenitrothion isomers, 3-methyl-4-nitrophenol, 3-methyl-6-nitrophenol, 3-methyI-4-nitroanisole, and bis-S-methyl fenitrothion. The total amount of the constituents quantitated in 9 commercial samples was 99.07 ± 1.81%. By comparing the amounts of bis-fenitrothion and phenols present in technical grade fenitrothion, it should be possible to identify the specific manufacturers of the various products.