Determination of 10 tobacco pesticide residues by magnetic QuEChERS combined with HPLC-MS/MS

To develop an analytical method combining magnetic QuEChERS and liquid chromatography- tandem mass spectrometry for the determination of 10 tobacco pesticide residues using magnetic carbon material (Fe₃O₄@C) as a purification adsorbent, the effects of Fe₃O₄@C prepared at different calcination temperatures on pesticide recovery were investigated and the application performance of Fe₃O₄@C was further systematically evaluated. The results showed that: 1) Good linearity (R > 0.992) was obtained for all the target pesticides at concentrations of 2-200 μg/L. 2) The repeatability for all the target pesticides at three spiked concentrations of 20, 50 and 200 μg/kg was satisfactory (RSD < 13.4%, n=6) and the recoveries ranged from 80.6% to 105.9%. The limits of detection (LODs) and limits of quantitation (LOQs) ranged from 0.05 to 0.67 μg/kg and from 0.18 to 2.23 μg/kg, respectively. The developed method is accurate and sensitive, simplifies the pretreatment process by magnetic recovery of Fe₃O₄@C, and is suitable for the quantitative analysis of 10 tobacco pesticide residues.