A method for multiresidue analysis of 48 pesticides (20 organophosphorus pesticides, 7 organochlorine pesticides, 14 organonitrogen pesticides, and 7 pyrethroid pesticides) permitted in Japan was systematically developed on the basis of capillary GC. Pesticides were simultaneously extracted with acetone from vegetable and fruit samples or with acetonitrile from lipid-containing crops and then re-extracted into ethyl acetate (test solution). Pesticides in the test solution were determined by capillary GC: Organophosphorus pesticides were directly determined by FPD-GC. Organonitrogen pesticides were determined by FTD-GC (NPD-GC) following cleanup by silica gel chromatography. Organochlorine and pyrethroid pesticides were measured by ECD-GC after cleanup by Florisil column chromatography. Recoveries for 10 crops a t fortification levels of 0.05-0.25 ppm were 42.5-128.5%. No pesticides tested here were detected except for banana, in which bitertanol was detected at 0.31 ppm.

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A rapid and sensitive method for the determination of fenoxaprop-ethyl in polished rice and brown rice by HPLC was developed. The pesticide was extracted from samples with acetonitrile. For polished rice, the extract was evaporated to dryness. For brown rice, the fats in the extract were removed with hexane saturated with acetonitrile, and the acetonitrile layer was evaporated to dryness. The residues were dissolved in hexane, and the hexane solution was cleaned-up with a Sep-pak(R) Florisil column. Recoveries of fenoxaprop-ethyl were 87. 2-104. 6% for polished rice and 88. 3-108. 3% for brown rice. No pesticide was found in 6 polished rice and 41 brown rice samples from the U. S. A.. The detection limits of fenoxaprop-ethyl in polished rice and brown rice were both 0. 01 ppm.