Tandem mass spectrometric analysis of quaternary ammonium pesticides

A detailed MSn study on an ion trap instrument of the quaternary ammonium p esticides paraquat, diquat, difenzoquat, mepiquat and chlormequat reveals a number of ions not reported previously, and has allowed examination of the fragmentation pathways. A number of transitions that are highly specific t o each quat have been identified. Optimal ion trap operating conditions det ermined using Simplex optimisation can promote either detection of a partic ular fragmentation transition or a range of MS/MS product ions with a high overall signal response. Thus, fragmentation conditions were optimised to e nhance the specificity or sensitivity of MS/MS methods. Copyright (C) 2001 John Wiley & Sons, Ltd.