比色法测定汽车材料中六价铬的不确定度评定

Evaluation of Uncertainty for Determination of Hexavalent Chromium in Automobile Materials by Colorimetric Method

探究基于比色法的汽车材料六价铬含量测定及其不确定度评定过程。试验中前处理方法为碱液消解法,测定汽车材料中的六价铬含量方法为紫外分光光度法,并对测量结果的不确定度进行评定。建立相关数学模型对该测试工作的测量不确定度来源、计算和结果表示等问题进行分析讨论。结果表明,测量结果不确定度的主要贡献者为标准溶液配置过程、测量重复性以及校准曲线拟合定量,测试过程中应予以关注。

This paper discussed the determination of hexavalent chromium content in automobile materials and its uncertainty evaluation process based on colorimetric method.Hexavalent chromium in automobile materials was determined by UV spectrophotometry with a pretreatment method of lye digestion,and the uncertainty of measurement results was evaluated.A mathematical model is established to analyze and discuss the source of uncertainty measurement,calculation and result representation.The results show that the preparation process of standard solutions,measurement repeatability and calibration curve fitting quantification are the main contributors to the uncertainty of measurement results,which should be paid attention to in the testing process.