The rapid analysis for residual pesticides by tandem mass spectrometry with immunoaffinity extraction

Abstract

A new strategy, based on immunoaffinity extraction coupled with flow-injection-electrospray tandem mass spectrometry (IAE-FI-MS/MS), has been developed for a screening method of phenoxy acid herbicides. This method uses polyclonal antibody produced against a protein for conjugating the phenoxy acid herbicides. Silvex, Mecoprop, Dichlorprop and 2,4-D were monitored in the multiple reaction monitoring (MRM) mode with the selection of m/z 267/195 for Silvex, m/z 213/141 for Mecoprop, m/z 233/161 for Dichlorprop and m/z 219/161 for 2,4-D, respectively. The use of highly selective IAE in sample preparation prior to FI-MS/MS analysis allowed the removal of interfering compounds present in the sample extracts, that would cause severe ionization suppression of the phenoxy acid herbicides during the electrospray process. In addition, the analysis time, including sample preparation and determination for 96 samples, required only 100 minutes for the screening for residual Silvex, Mecoprop, Dichlorprop and 2,4-D by using a 96-well microtiter plate.