Comparative study of pesticide multi-residue extraction in tobacco for gas chromatography-triple quadrupole mass spectrometry.

This study was performed to apply the more rapid and accurate sample preparation, and the high selectivity and sensitivity of the analyte detection by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). We compared with the three-sample preparation methods of pesticide residues in tobacco such as the conventional liquid-liquid extraction (LLE), pressurized liquid extraction (PLE) and QuEChERS (quick, easy, cheap, effective, rugged and safe) methods. These methods were validated for 49 pesticides in the CORESTA Agrochemical Advisory Committee guide and amenable to GC-MS/MS determination. LLE with acetonitrile, and PLE with acetone were followed by solid-phase extraction (SPE) and analyzed by GC-MS/MS. In QuEChERS method, the effects of sorbents, such as primary secondary amine (PSA), octadecylsilane (C(18)) and graphitized carbon black (GCB), and matrix of the analytes in tobacco types, such as flue-cured, burley and oriental were investigated. MS/MS acquisition provided high specificity and selectivity for pesticides and low limit of detection and quantification. QuEChERS by using PSA alone and the matrix-matched standards gave good recoveries and RSD values in three types of tobaccos. The method yielded higher and more consistent recoveries of these analytes than LLE and PLE. QuEChERS method was no needed to be complex clean-up procedure and would be used to rapid and sensitive analysis of pesticides as an alternative to LLE and PLE methods.