The role of the liquid chromatography-mass spectrometry in pesticide residue determination in food

The use of liquid chromatography (LC) in pesticide residue determination was usually limited to groups of compounds or single compounds for which no suitable gas chromatographic (GC) conditions were available. However, recent developments have significantly enlarged the LC scope in this field of analysis. One of the most important advances was the on-line coupling of efficient LC separation with mass spectrometry detectors (LC-MS and LC-MS/MS) that makes this technique an excellent method for the determination of pesticides and their transformation products in complex matrices such as food. This review considers the application of LC-MS/MS in this field. Emphasis is placed on the tandem MS applications: advantages of the technique; the sensitive and unequivocal confirmation of the presence of pesticides in food; and, important factors affecting the performance of LC-MS/MS instruments, like the type of mass analyzer or the ionization source design which would be discussed on the particular framework of pesticide and their metabolite analysis. This review also highlights a number of problems associated with the LC-MS/MS analysis of pesticides such as the matrix effects that make quantification difficult.