Objective To evaluate the uncertainty evaluation for the determination of imidacloprid in Caidian lotus root by ultra performance liquid chromatography-tandem quadrupole mass spectrometry. Methods According to GB/T 20769 - 2008 Determination of 450 pesticides and related chemicals residues in fruits and vegetables-Liquid chromatography-tandem mass spectrometry, the content of imidacloprid in Caidian lotus root was determined and the mathematical model was built. According to the provisions of JJF 1135-2005 Evaluation of measurement uncertainty in chemical analysis and JJF 10591-2012 Technical specification for evaluation and representation of measurement uncertainty, the uncertainty was quantified by scientific analysis, and the extended uncertainty of imidacloprid content in Caidian lotus root　was finally calculated. Results When the residue imidacloprid in Caidian　lotus root was ${0.322}\mathrm{{mg}}/\mathrm{{kg}}$ , the　relative standard synthetic uncertainty was 0.08689 and the expanded　uncertainty was ${0.0560}\mathrm{{mg}}/\mathrm{{kg}}$ . The　determination results were　 $\left({{0.322}\pm {0.0560}}\right)\mathrm{{mg}}/\mathrm{{kg}},P ={95}\%, k = 2$ . Conclusion The main sources of uncertainty in　the determination of imidacloprid in Caidian lotus root by ultra　performance liquid chromatography-tandem quadrupole mass spectrometry　are the preparation of standard solution, sample pretreatment and　measurement process of the measuring instrument.

ultra performance liquid chromatography-tandem quadrupole mass spectrometry  /  Caidian lotus root  /  imidacloprid  /  uncertainty evaluation