微波消解-石墨炉原子吸收光谱法测定鲤鱼肌肉中镉含量的不确定度分析

Uncertainty evaluation for determination of cadmium in carp (Cyprinus carpio L.) by graphite furnace atomic absorption spectrometry with microwave digestion

中文关键词:  微波消解  石墨炉原子吸收光谱法  镉  不确定度

英文关键词:microwave digestion  graphite furnace atomic absorption spectrometry  cadmium  uncertainty evaluation

中文摘要:

      目的 评定微波消解-石墨炉原子吸收光谱法测定鲤鱼(Cyprinus carpio L.)肌肉中镉含量的不确定度。方法 采用微波消解-石墨炉原子吸收光谱法测定鲤鱼肌肉中的镉含量, 并根据JJF1059-2012《测量不确定度评定与表示》的有关规定, 构建数学模型, 对各部分不确定度的分量进行分析。结果 鲤鱼肉中镉含量为0.0104 mg/kg, 包含因子取k=2, 扩展不确定度为0.00106 mg/kg。同时对测定结果的不确定度的各部分影响因素进行了量化, 样品消解液定容产生的相对标准不确定度urel(V)为0.002915, 样品上机检测的浓度产生的相对标准不确定度ure1(C)为0.04527, 样品质量m产生的相对标准不确定度urel(m)为0.007292, 修正系数产生的相对标准不确定度urel(f)为0.02222。结论 本实验的不确定度主要由样品上机检测的浓度产生, 其中包括样品的重复测定、标准曲线拟合及标准溶液配制, 其次由样品前处理产生。

英文摘要:

      Objective To evaluate of the uncertainty in the determination of cadmium in carp (Cyprinus carpio L.) by graphite furnace atomic absorption spectrometry with microwave digestion. Methods According to the standard of JJF1059-2012 Evaluation and expression of uncertainty in measurement, the content of cadmium in muscle of carp was determined by graphite furnace atomic absorption spectrometry with microwave digestion. The mathematical model was constructed and the components of the uncertainty of each part were analyzed. Results The cadmium content of carp meat was 0.0104 mg/kg, with the inclusion factor of k=2, and the extension uncertainty was 0.00106 mg/kg. At the same time, the factors affecting the uncertainty of the results were quantified. The relative standard uncertainty of the capacity volume was 0.002915, the relative standard uncertainty of sample concentration was 0.04527, the relative standard uncertainty of sample quality was 0.007292, and the relative standard uncertainty of the correction coefficient was 0.02222. Conclusion The uncertainty of the experiment is mainly caused by the concentration detected on the sample, including the repeated determination of the sample, the fitting of standard curve and the preparation of standard solution, followed by sample pretreatment.