Application of capillary gas chromatography with mass selective detection to pesticide residue analysis

Abstract

A random sample of 76 pesticides with good gas chromatographic properties has been collected in order to test the applicability of the mass selective detector HP MSD for pesticide residue analysis. Using a capillary column, mass spectra of good quality were produced with 10 or 20 ng of each pesticide. Seventy two compounds were not only identified at this concentration with the PBM (probability based matching) search routine in the NBS library, but also remarkably with the best fit in the corresponding hit list. Lower concentrations can be detected only with selected ion monitoring (SIM). A mixture of 18 chlorinated pesticides was added to green pepper at the 10 ppb level. All compounds were detected with SIM using special time programming in one gas chromatogaphic analysis. The detection sensitivity of the mass selective detector in SIM mode approaches that of established selective detectors. The reliability of the results with respect to the identity of a pesticide residue, however, is orders of magnitude better. Therefore, this detector is a valuable tool for performing confirmatory analysis.