Objective To explore the main factors of uncertainty in the determination of 33 pesticide residues in ginseng by gas chromatography-tandem mass spectrometry.Methods 33 pesticide residues in ginseng were determined by gas chromatography-tandem mass spectrometry.According to the requirements of JJF 1059.1-2012"Evaluation and Expression of Uncertainty in Measurement"and JJF 1135-2005"Evaluation of Uncertainty in Chemical Analysis Measurement",the mathematical model of uncertainty evaluation was established.Each component is evaluated by analyzing the main sources of uncertainty in the determination process,namely the weighing of the samples,the dilution of the standard solution,the pretreatment of the samples,and the repeatability of the instrumental determination.Results The average recovery rate of samples ranged from 79.61%to 116.70%.The extended uncertainty of 33 pesticide residues measured in the range of 0.010 to 0.20 mg·kg-1 was±0.000 718 to±0.025 2 mg·kg-1.Conclusion This method provides a theoretical basis for the determination of 33 pesticide residues in ginseng by gas chromatography-tandem mass spectrometry near the critical point.
Gas chromatography-tandem mass spectrometryGinsengPesticide residueSimultaneous determinationEvalution of uncertainty