Multiresidue method for determination of organophosphorus pesticides in vegetables.

A multiresidue method for the analysis of 14 organophosphorus pesticides has been developed for the rapid control of residues in vegetables before processing. The residues were extracted in ethyl acetate; the extracts were dried, purified using an Extrelut 20 column and, after concentration, analysed by gas chromatography with a nitrogen phosphorus detector. Recoveries performed in asparagus, beans, French beans, spinach, peas and zucchini at three fortification levels were over 77% for all pesticides except dementon-S-methyl (70%) and omethoate (52%).