Abstract
A simple and rapid sample preparation method was developed for the determination of carbamate pesticides in agricultural products. The method consisted of methanol extraction, purification by addition of zinc sulfate and sodium tetraborate and reextraction with dichloromethane.
Heat-labile carbamate pesticides were hydrolyzed with NaOH and determined by gas chromatography-mass spectrometry after benzyl derivatization.
The recoveries of 12 kinds of carbamate pesticides fortified at 0.04-0.4ppm in 15 kinds of samples ranged from 63.8 to 134.8% with detection limits of 0.005-0.02ppm, depending on the compounds.
The procedure was applied to 309 products. Methomyl or thiodicarb was detected at 0.02-0.15ppm in four domestic vegetables (cucumber, eggplant, etc.). Carbaryl was detected at 0.01-0.09ppm in seven fruits (orange, apple, etc.).
