离子色谱法测定水中锂离子的不确定度评定

Evaluation of Uncertainty in Determination of Lithium Ions in Water by Ion Chromatography

离子色谱法作为水中锂离子的检测方法之一,测量结果的准确性受多种因素的影响,为了减少误差同时提高检测准确度,评定离子色谱法测定锂离子的不确定度尤为重要。研究围绕水中锂离子测定的准确性,从4个方面系统地进行了不确定度评估:重复性测量、标准溶液的配制过程、标准曲线的线性回归分析以及离子色谱仪器。依据既定的标准,独立计算了各分量的不确定度,通过计算得出总体的合成不确定度、扩展不确定度指标。结果表明,经由该方法所获得的水中锂离子浓度的合成相对标准不确定度为0.0093,而相应的扩展不确定度为0.019 mg/L。其中对合成相对标准不确定度影响最大的两个不确定度分量为标准溶液的配制过程及离子色谱仪器。

Ion chromatography is one of the detection methods for lithium ions in water,the accuracy of the measurement results is affected by many factors.In order to reduce the error and improve the detection accuracy,it is particularly important to evaluate the uncertainty of ion chromatography for the determination of lithium ions.In this study,the accuracy of lithium ion determination in water was systematically evaluated from four aspects:repeatability measurement,standard solution configuration process,linear regression analysis of standard curve,and ion chromatography instrument.According to the established standard,the uncertainty of each component was calculated independently,and the overall composite uncertainty and extended uncertainty index were obtained through calculation.The results showed that the synthetic relative standard uncertainty of the lithium ion concentration in water obtained by this method was 0.0093,and the corresponding extended uncertainty was 0.019 mg/L.And the two uncertainty components that have the greatest influence on the synthetic relative standard uncertainty were the preparation process of standard solution and the ion chromatography instrument.