Abstract
We developed a new analytical method for analysis of N‐methyl carbamate pesticides in cereals and beans using dual counter‐current chromatography (dual CCC) and liquid chromatography‐electrospray ionization tandem mass spectrometry (ESI LC/MS/MS). After pesticides were extracted from cereals and beans with ethyl acetate, each extract was cleaned up by dual CCC using a non‐aqueous binary solvent system composed of n‐hexane‐acetonitrile and analyzed by ESI LC/MS/MS with a short column. The average recoveries from cereals and beans fortified at the level of 0.01 ppm ranged from 73.9 to 119.6%, with the coefficients of variation from 0.7 to 6.8%. At the fortified level of 0.5 ppm, the recoveries ranged from 72.1 to 117.1% with coefficients of variation from 0.4 to 9.3%. The present analytical method of N‐methyl carbamate pesticides in cereals and beans is considered to be useful for monitoring the pesticide residues in cereals and beans.
Acknowledgment
The authors wish to thank Mrs. Y. Yoshimi for carrying out some of the experiments.