GC/MS AND LC/MS DETERMINATION OF 20 PESTICIDES FOR WHICH DIETARY ONCOGENIC RISK HAS BEEN ESTIMATED

The National Research Council has estimated dietary oncogenic risk for 28 pesticides registered for use in the United States. We report a rapid analytical procedure for 20 of these pesticides in a variety of crops based on a single extraction step and the use of mass spectrometry for detection and quantification. Recovery and sensitivity studies were performed in various commodities (apples, peaches, potatoes, tomatoes, peppers, spinach, lettuce, snap beans, and sweet corn) for the suspected oncogens acephate, alachlor, azinphos-methyl, captafol, captan, chloridimeform, chlorothalonil, cypermethrin, diclofopmethyl, ethalfluralin, metolachlor, oxadiazon, parathion, permethrin, pronamide, o-phenylphenol, terbutryne, folpet, linuron, and oryzalin. All pesticides were determined by gas chromatography/chemical ionization mass spectrometry (GC/CIMS) except the last three, for which high-performance liquid chromatography/mass spectrometry (HPLC/MS) was used. Average recoveries at the 0.5 ppm fortification level were between 70 and 123%, with an average coefficient of variation of 13%. Sensitivity studies demonstrated that most pesticides could be detected at 0.05 or 0.10 ppm in the crops, but some limits of detection were 0.25 ppm or greater.