PREPARATION OF SOME TOXIC METABOLITES OF DISULFOTON, PHORATE, AND TERBUFOS, THEIR SEPARATION BY THIN-LAYER CHROMATOGRAPHY AND CONFIRMATION BY ELECTRON-IMPACT MASS-SPECTROMETRY

Milligram quantities of sulfoxides, sulfones, and oxygen analogue (oxo n) sulfones of the insecticides disulfoton, phorate, and terbufos were prepared by selective oxidation. Pure insecticides or acetone extract s of granular formulations served as reactants. Structures of 9 compou nds were confirmed by comparing their electron impact mass spectra (EI -MS), obtained by the direct inlet system with published data. Thin-la yer chromatography (TLC) on silica gel was used to screen oxidation pr oducts and to purify products. Products were detected by spraying plat es with PdCl2 reagent and exposing to iodine vapors. An esterase inhib ition technique gave low detection limits, which are promising for res idue analysis.