微波消解-火焰原子吸收光谱法测定茶叶中铅含量的不确定度评定

Evaluation of Uncertainty in Determination of Lead in Tea by Microwave Digestion-Flame Atomic Absorption Spectrometry

本实验利用微波消解-火焰原子吸收光谱法测定茶叶中铅含量,同时也对影响测定结果的不确定度来源进行了分析评定。评定结果表明:影响测定结果的不确定度来源主要有检测仪器、标准曲线拟合、溶液稀释等。测定结果显示:当取样量为0.4999 g,k=2(95%置信度)时,茶叶中铅含量为(1.095±0.05076)mg/kg。

In this study,the lead content in tea was determined by microwave digestion-flame atomic absorption spectrometry,and the sources of uncertainty affecting the determination results were analyzed and evaluated.The evaluation results showed that the main sources of uncertainty affecting the results were the measuring instrument(atomic absorption spectrophotometer),the fitting of standard curve,the dilution of solution and so on.The determination results indicated that the lead content was 1.095±0.05076mg/kg,when the sample mass was 0.4999 g,k=2(confidence of 95%).