Dual‐layer column filtration cleanup and gas chromatography‐tandem mass spectrometry detection for the analysis of 39 pesticide residues in porcine meat

A rapid and effective method was developed for the analysis of 39 pesticide residues in porcine meat with dual‐layer multiplug filtration cleanup and gas chromatography‐tandem mass spectrometry detection. The cleanup process was performed with columns packed with two layers, namely multiwalled carbon nanotubes, C18 and anhydrous magnesium sulfate (MgSO₄) as top layer, while mixture of florisil and MgSO₄ as bottom layer. A single‐layer method was tested in parallel, with columns packed with the same amount of absorbents. Extraction conditions and filtration cleanup process were optimized to obtain satisfied method performance. Method linearity was calculated with coefficients of determination more than 0.995. The limits of quantitation were verified with acceptable accuracy at the lowest spiked concentration of 0.01 mg/kg (except pyrimethanil). The recoveries at three fortified levels (0.01, 0.05, and 0.1 mg/kg) in five replicates were between 74 and 118% (except pyrimethanil) with relative standard deviations range from 1 to 16%. The matrix effects were in the range of 1.01 to 2.84. This new method was applied for the analysis of multipesticide residues in market samples of porcine meat. This study showed the dual‐layer multiplug filtration cleanup demonstrated better performance than that with the single‐layer columns in cleanup of porcine meat.