GF-AAS与ICP-MS测定水中总铬含量的方法比对及其不确定度评定

Comparison of Determination Methods between GF-AAS and ICP-MS for Total Chromium Content in Water and the Uncertainty Evaluation

石墨炉原子吸收光谱(GF-AAS)法和电感耦合等离子体质谱(ICP-MS)法是灵敏度较高的2种测定水中铬含量的方法。文中采用357.9 nm与429.0 nm波长条件下GF-AAS法、52与53质核比条件下ICP-MS法测定水质铬标准物质中总铬元素含量,从标准曲线、准确性、重复性、加标回收率、检出限、定量限、测量不确定度评定多个方面进行对比分析。结果表明,4组测定条件下,标准物质测定结果均在标准值不确定度范围内。其中,429.0 nm波长GF-AAS法测定结果相对其他3组显著偏低(P<0.05);ICP-MS法在检出限、定量限方面优于GF-AAS法;GF-AAS法测定结果357.9 nm波长优于429.0 nm波长。

Graphite furnace atomic absorption spectrometry(GF-AAS)and inductively coupled plasma mass spectrometry(ICP-MS)are two methods for determining the Cr content in water with high sensitivity.In this paper,GF-AAS methods at 357.9 nm and 429.0 nm wavelength and ICP-MS methods at 52 and 53 mass nuclear ratio were used to determine the content of total chromium in chromium reference materials for water quality.A comparative analysis was made from the aspects of standard curve,accuracy,repeatability,standard recovery rate,detection limit,quantitation limit and evaluation of measurement uncertainty.The results showed that the determination results of reference materials were within the scope of the standard uncertainty.The results of 429.0 nm wavelength GF-AAS method were significantly lower than other determination methods(P<0.05).ICP-MS method was better than GF-AAS method in terms of detection limit and quantitation limit.In GF-AAS method,357.9 nm wavelength was better than 429.0 nm wavelength.