title: Gas chromatographic method for determination of fenitrothion in technical and in emulsifiable concentrate and water-dispersible powder formulations: collaborative study.
abstract: A variety of column packings and internal standards were evaluated to determine the most satisfactory system to use in a gas chromatographic (GC) method for analysis of fenitrothion, technical and formulations. Fenitrothion and the most closely related isomer, O,O-dimethyl O-(4-methyl-3-nitrophenyl) phosphorothioate, were resolved on columns packed with OV-210 and with polyphenyl ether, 6-ring (PPE-6R). A method based on the separation of fenitrothion on a PPE-6R column with fluoranthene as internal standard was selected for use in a limited collaborative trial and later for use in a full-scale collaborative trial with 21 collaborators participating. Each collaborator was furnished matched pairs of samples of technical fenitrothion, emulsifiable concentrate, and water-dispersible powder. The coefficients of variation (CV) for the paired samples were 1.02, 1.11, and 1.01, respectively, for technical fenitrothion, emulsifiable concentrates, and water-dispersible powders. Data are also presented for an alternative method in which compounds are separated on an OV-210 column with dibutyl sebacate as the internal standard. The method has been adopted official first action.
mesh_terms: D002849:Chromatography, Gas; D004655:Emulsions; D005278:Fenitrothion / Q000032:analysis*; D011208:Powders
chemical_list: D004655:Emulsions; D011208:Powders; D005278:Fenitrothion