Many pesticides, which are difficult or generally not to analyse by GC/MS, can be identified and quantified by LC/MS/MS. After simple solvent extraction and fast cleanup the extracts are analysed using matrix-matched standards. The drawback of MS/MS methods is laborious parameter optimization for each target analyte. This effort can significantly be reduced by the use of standard parameters, which are given in the attached CD ROM.
Actually more than 800 pesticides are used worldwide. For many of these compounds legal action levels (e.g. maximum residue limits or tolerances) in food exist, which have to be controlled. For this type of target analysis multi residue analytical methods are preferred to reduce the workload. Up to now, such methods based on LC/MS/MS had been published for a reduced number of pesticides only. Furthermore, there is no knowledge about the maximum number of compounds, which can be determined simultaneously.
Extraction and cleanup procedures are described in Figure 1. Using the
readyfor- use method files on the CD ROM in combination with API 2000,
API 3000, and API 4000 LC/MS/MS Systems following pesticides and their
metabolites can be identified and quantified: 3,4,5-trimethacarb, 3-hydroxycarbofuron,
5-hydroxyclethodimsulfone, 5-hydroxythiabendazole, acephate, aldicarb,
aldicarbsulfoxide, aldoxycarb, amidosulfuron, atrazine, azoxystrobin,
bendiocarb, bensulfuronmethyl, butocarboxim, butocarboxim-sulfoxide, butoxycarboxim,
carbaryl, carbendazim, carbofuran, chlorsulfuron, cinosulfuron, clethodim,
clethodimiminsulfone, clethodimiminsulfoxide, clethodimsulfone, clethodimsulfoxide,