DETERMINATION OF DICHLORVOS, TRICHLORFON AND THEIR METABOLITES AND DEGRADATION PRODUCTS IN ENVIRONMENTAL WATER, DRINKS AND HUMAN URINE

A systematic analytical procedure for dichlorvos (DDVP) and trichlorfo n (DEP), organophosphorus pesticides, and furthermore for desmethyl di chlorvos (DM-DDVP), desmethyl trichlorfon (DM-DEP), dimethyl phosphate (DMP) and monomethyl phosphate (MMP), their metabolites and degradati on products, was investigated. From the environmental water, drinks an d human urine, after salting-out, only DDVP was first extracted with n -hexane and then the others were extracted with acetonitrile-diethylet her (1:1, v/v) at about 1N by HCl. TLC was performed on silica-gel pla te using acetonitrile-water (85:15, v/v) and isopropanol-water-28% amm onium hydroxide (75:24:1, v/v) as development systems. By colorations with 4-(P-nitrobenzyl) pyridine (NBP) and o-tolidine, they were relati vely well detected. It was possible to determine DEP, DM-DDVP, DM-DEP, DMP and MMP by FID-GC and GC-MS after trimethylsilyl derivatization o f them with N,O-bis (trimethylsilyl) trifluoroacetamide (BSTFA). The d etection limits of their aqueous solution were 0.1-3 mu g/ml by FID-GC and 0.2-10 mu g/ml by scanning made GC-MS. The coefficients of variat ion for their spiked urine sample by GC analysis in this way were 2.7- 7.6% at 50 mu g/ml, respectively.