Determination of 49 pesticide residues in tobacco by gas chromatography-tandem mass spectrometry

A method was developed for rapid determination of 49 pesticide residues in tobacco based on gas chromatography-tandem mass spectrometry (GC-MS/MS). Tobacco was extracted with 0. 1% acetic acid-acetonitrile solution. The supernatant was quantitatively transferred and dried with nitrogen. The concentrated extract was dissolved with acetonitrile-ethyl acetate (l:1, v/v) solution and cleaned up by primary secondary amine (PSA) sorbents, MgSO4 and C18 sorbents, then determined by GC-MS/MS with mirex as internal standard. The ranges of spiked recoveries of 49 pesticides at 0. 05 mu g/L and 5 mu g/L were 60.4% - 104.8% and 70% 115% , respectively. The relative standard deviations were below 15%. The detection limits of 16 pesticides were 0.01 -0.03 mu g/kg and those of the other 33 pesticides were less than 0.01 mu g/kg; the correlation coefficients were larger than 0.991. This method is simple, rapid and characterized with acceptable sensitivity and accuracy to meet the requirements for the analysis of multiple pesticide residues in tobacco.