Comprehensive screening of target, non-target and unknown pesticides in food by LC-TOF-MS

In pesticide residue analysis (PRA), as well as traditional quantitative analysis of target compounds – mainly pesticides in their parent form – there is now remarkable interest in screening pesticides in a comprehensive way, including not only common pesticides but also less common or relatively new pesticides (non-target) or unknown transformation products (unknowns).To address this interest, liquid chromatography coupled to mass spectrometry (LC-MS) with time-of-flight (TOF) analyzers (TOF-MS or QTOF-MS) is most suitable, taking into account accurate mass analysis, resolving power, enhanced selectivity and high sensitivity in full-scan acquisition mode.In this article, we discuss the main features and the advantages of LC-TOF-MS instruments for PRA in food – advantages and pitfalls of the instruments. We make a critical comparison, including examples, of the application of LC-TOF-MS to screening, identification and confirmation of target, non-target and unknown pesticides in foodstuffs.