液相色谱-高分辨质谱法测定豆芽中4-氯苯氧乙酸的不确定度评估

Uncertainty evaluation for determination of 4-chlorophenoxyacetic acid in bean sprouts by liquid chromatography-high resolution mass spectrometry

目的评定液相色谱串联高分辨质谱法测定豆芽中4-氯苯氧乙酸含量的不确定度。方法按照SN/T3725-2013《出口食品中4-氯苯氧乙酸残留量的测定》测定豆芽中4-氯苯氧乙酸,根据JJF 1059.1-2012《测定不确定度评定与表示》的方法,建立高分辨液质联用法测定豆芽中4-氯苯氧乙酸不确定度评定的数学模型,分析其中各不确定度分量的来源,并对其分别进行量化,最终合成豆芽中4-氯苯氧乙酸含量测定结果的不确定度。结果豆芽中4-氯苯氧乙酸含量测定结果为35.11μg/kg时,在95%的置信区间下,扩展不确定度为4.28μg/kg(k=2)。结论标准溶液的配制是实验过程不确定度主要来源。

Objective To evaluate the uncertainty for the determination of 4-chlorophenoxyacetic acid in bean sprouts by liquid chromatography-high resolution mass spectrometry. Methods According to SN/T 3725-2013 Determination of 4-chlorophenoxyacetic acid residues in food for export, content of 4-chlorophenoxyacetic acid in bean sprouts was detected. According to JJF 1059.1-2012 Evaluation and expression of measurement uncertainty, a mathematical model for the evaluation of the uncertainty of 4-chlorophenoxyacetic acid in bean sprouts by high-resolution liquid chromatography-mass spectrometry was established, the sources of each uncertainty component was analyzed and quantified, and 4-chlorophenoxy in bean sprouts uncertainty in the determination of acetic acid content was synthesized. Results When the content of 4-chlorophenoxyacetic acid in bean sprout was 35.11 μg/kg, the expanded uncertainty was 4.28 μg/kg(k=2) under 95% confidence interval. Conclusion The preparation of standard solution is the main source of uncertainty in experimental process.