液相色谱-串联质谱法测定黄瓜中多菌灵含量的测量不确定度评定

Uncertainty evaluation for determination of carbendazim in cucumber by LC-MS-MS method

目的评定用液相色谱-串联质谱法测定黄瓜中多菌灵含量的测量不确定度,找出影响的主要因素。方法依据JJF1059.1-2012《测量不确定度评定与表示》的方法和JJF 1135-2005《化学分析不确定度评定》中最小二乘法拟合标准曲线的实例建立测量模型,分析不确定度来源,评定各分量的不确定度,再计算合成标准不确定度、扩展不确定度。结果黄瓜中多菌灵含量报告为(0.001 23±0.000 22)mg/kg。结论拟合标准曲线方程计算试液含量环节和测量重复性是测量不确定度的主要来源,若改善这两个环节,可以提高检测的准确度和可靠性。

[Objective]To estimate the measurement uncertainty in the determination of carbendazim in cucumber by LC-MS-MS method, and find out the primary influencing factors.[nethods]A mathematic model was established according to the example of fitting standard curve using least square method in JJF1059.1-2012 ＂Evaluation and Representation of Measurement Uncertainty＂ and the method in JJF1135-2005 ＂Evaluation of Chemical Analysis Uncertainty＂. Then the source of the measurement uncertainty was analyzed, uncertainty of each component was evaluated, the combined standard uncertainty and the extended uncertainty were calculated finally.[Results]The reported result of carbendazim in cucumber was（0.001 23：1：0.000 22） mg/kg.[Conclusion]The standard curve fitting procedure to calculate carbendazim content in sample solution and repeatability of measurement are the most critical factors of the estimation of measurement uncertainty, so more attention should be paid on those 2 fields to improve the accuracy and reliability of determination.