Analysis of Acephate and Methamidophos in Agricultural Products by GC

When acephate and methamidophos in agricultural products were determined by GC-FPD, the recoveries were more than 100%. We therefore prepared a standard solution for analysis of the pesticides by dissolving acephate and methamidophos in yeast extract solution, and used it as a calibration standard. The detection limits of acephate and methamidophos were 0.01ppm for agricultural products. Recoveries of acephate and methamidophos added to agricultural products at 0.1ppm and 0.05ppm were 97-99% and 80-92%, respectively. The present method was applied to the analysis of 447 agricultural products. Acephate and methamidophos were detected in 12 samples. The levels of acephate residues in 10 samples were 0.03-1.2ppm and the levels of methamidophos residues in 7 samples were 0.01-4.3ppm.