Multi-Residue Analysis of Pesticides in Samples of Lettuce and Peas Using Large Volume-Difficult Matrix Introduction-Gas Chromatography-Mass Spectrometry (LV-DMI-GC-MS)

Ethyl acetate is widely used as a solvent for the multi-residue extraction of pesticides from foods because it provides acceptable recovery over a wide range of polarity. Prior to GC analysis of the extracts, some form of clean up (e.g. SPE, GPC) is usually necessary to remove the matrix co-extractives. These cause rapid contamination of the GC system (injector and column), and subsequent deterioration of chromatographic performance. The clean-up techniques increase the sample preparation time, solvent usage, and hence the cost of the analysis.