高效液相色谱-电感耦合等离子体质谱联用法测定茶叶中铬酸根含量的不确定度评定

Uncertainty evaluation for the determination of chromate in tea by high performance liquid chromatography-inductively coupled plasma mass spectrometry

目的评定高效液相色谱-电感耦合等离子体质谱联用法测定茶叶中铬酸根含量的不确定度。方法通过建立不确定度评定的数学模型,分析并计算各不确定度分量,计算合成不确定度和扩展不确定度,得出影响结果不确定度的主要来源。结果在95%的置信区间下,当茶叶中铬酸根的含量为113.2 mg/kg时,扩展不确定度U=8.9mg/kg(k=2)。结论影响结果不确定度的主要因素是样液浓度引入的不确定度,其中由拟合曲线求得样液浓度引入的不确定度影响最大。

Objective To evaluate the uncertainty in the determination of chromate in tea by high performance liquid chromatography-inductively coupled plasma mass spectrometry. Methods Through the establishment of the uncertainty evaluation mathematical model, the components of uncertainty were analyzed and calculated, the composite uncertainty and extended uncertainty were calculated, and the main source of uncertainty that affected the results were obtained. Results Under the 95% confidence interval, when the content of chromate in tea was 113.2 mg/kg, the expanded uncertainty was U=8.9 mg/kg(k=2). Conclusion The main factor that affects the uncertainty of the results is the uncertainty introduced by the concentration of the sample solution, and the uncertainty introduced by sample concentration obtained by fitting curve has the greatest influence.