UPLC-MS/MS法测定元胡中4种有机磷农药残留的不确定度评定

目的]对采用超高效液相色谱-串联质谱法(UPLC-MS/MS)测定元胡中4种有机磷农药残留的不确定度进行评估。方法]根据JJF 1135—2005《化学分析测量不确定度评定》和JJF 1059.1—2012《测量不确定度评定与表示》中的有关规定,采用UPLC-MS/MS法测定元胡中4种有机磷农药残留。建立测定元胡中4种有机磷残留量不确定度的数学模型,逐层对不确定度来源进行分析,计算各不确定度分量并合成出标准不确定度和扩展不确定度。结果]当试样中马拉硫磷含量为0.048 57μg/kg时,其扩展不确定度为(0.048 57±0.011 55)μg/kg,包含因子k=2;当试样中氧化乐果含量为0.065 34μg/kg时,其扩展不确定度为(0.065 34±0.016 41)μg/kg,包含因子k=2;当试样中水胺硫磷含量为0.043 14μg/kg时,其扩展不确定度为(0.043 14±0.011 02)μg/kg,包含因子k=2;当试样中三唑磷含量为0.058 36μg/kg时,其扩展不确定度为(0.058 36±0.013 02)μg/kg,包含因子k=2。结论]影响测定结果不确定度的主要来源为添加回收、标准溶液配制的准确性、测定重复性和方法的准确度,其他因素的影响相对较小。

Uncertainty Evaluation of Determination of Organic Organophosphorus Residues in Corydalis yanhusuo by UPLC-MS/MS

Objective] This study aimed to evaluate the uncertainty of measurement in the determination of organic organophosphorus residues in Corydalis yanhusuo by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).Method] According to JJF 1135-2005.Evaluation of Uncertainty in Chemical Analysis Measurement and JJF 1059.1-2012 Evaluation and Expression of Uncertainty in Measurement,a mathematical model was established for uncertainty evaluation.The sources of uncertainty that may be introduced were analyzed and each component of uncertainty was quantified for the calculation of the combined uncertainty.Result] The expanded uncertainty of (0.048 57 ±0.011 55) μg/kg (k =2) was obtained for the determination of the presence of 0.048 57 μg/kg malathion;the uncertainty of (0.043 14 ±0.011 02) μg kg (k =2) was obtained for the determination of the presence of 0.043 14 μg/kg isocarbophos;the uncertainty of (0.065 34 ±0.016 41) μg/kg (k =2) was obtained for the determination of the presence of 0.065 34 μg/kg omethoate;the uncertainty of (0.058 36 ±0.013 02)μg/kg (k =2) was obtained for the determination of the presence of 0.058 36 μg/kg triazophos.Conclusion] The preparation of standard solution,curve fitting and measurement repeatability were found to be the main sources of uncertainty.