DETERMINATION OF DEBROMO-BROMOBUTIDE AND 14 ORGANONITROGEN PESTICIDESSUCH AS DIMEPIPERATE IN AGRICULTURAL PRODUCTS BY GC

An analytical method for 15 chemicals including dimepiperate, thenylch lor, probenazole, bromobutide and debromo-bromobutide has been develop ed by modifying the Japanese official analytical method for 10 organon itrogen pesticides notified in September 1993. Ten grams of grain or 2 0 g of vegetable or fruit was homogenized with acetone followed by ext raction with ethyl acetate, and the extract was evaporated. In the cas e of grains, fat or oil was removed from the extract by n-hexane-MeCN partitioning. Then the extract was purified by Florisil column chromat ography and concentrated to 5 ml. The concentrations of pesticides wer e determined by FTD-GC. Esprocarb, diethophencarb and thiobencarb in w heat could not be determined by FTD-GC because of interfering peaks, s o they were determined by GC/MS (SIM). The recoveries of 15 chemicals in ten kinds of fortified agricultural products were 65.9 similar to 1 03.4% when they were fortifred at levels of 0.5 ppm for probenazole an d 0.1 ppm for the others. Detection limits were 0.005 to 0.05 ppm for each pesticide.