滤膜中锡测定方法的改进及不确定度评定
Improvement of Determination Method for Tin Content in Filter Membranes and UncertaintyEvaluation
-
摘要:
目的 对GBZ/T 160.22《工作场所空气中锡及其化合物浓度的测定》中滤膜中锡的原子吸收光谱测定方法进行改进,建立快速、准确测定滤膜中锡的方法。并对滤膜中锡的测定结果进行不确定度评定。 方法 用3.0 mL盐酸和0.5 mL硝酸消解滤膜,火焰原子吸收法测定。并分析其测定不确定度的主要来源,按照JJF 1059.1-2012的有关规定对测定结果的不确定度进行评定。 结果 锡在0~60 μg/mL范围内线性关系良好,相关系数r > 0.999,方法的检出限为0.87 μg/mL,加标回收率为100.8%~102.6%,相对标准偏差为1.5%~3.9%。不确定度的评定结果显示,测定结果的不确定度主要来源于样品前处理、标准溶液、标准曲线和仪器测定重复性等方面。 结论 改进后的方法稳定性及准确度均优于国标方法,更适用于滤膜中锡的含量测定。 Abstract:Objective To establish a rapid and accurate method for determination of tin content in filter membranes through improving the atomic absorption spectroscopy method provided by the Methods for Determination of Tin and ItsCompounds in the Air of Workplace (GBZ/T 160.22),and evaluate the measurement uncertainty of the method. Methods The filter membranes were digested with 3.0 mL hydrochloric acid and 0.5 mL nitric acid,followed by flame atomic absorption spectrometry to detect tin.The uncertainty of the results was evaluated according to JJF 1059.1-2012. Results The calibration curve of the proposed method was linear within the range of 0-60 μg/mL,the detection limit for tin was 0.87 μg/mL,and the average recoveries ranged from 100.8% to 102.6% with the relative standard deviations between 1.5% and 3.9%.In the results of uncertainty evaluation,sample pre-treatment,standard solution,calibration curve,and the measurement repeatability ofthe equipment were main contributors to the uncertainty of the proposed method. Conclusion The revised method possesses better stability and accuracy than the national standard method,so it could be more suitable for determination of tin in filter membranesgroup
下载:
