不确定度在涂料分析研究中的应用

Application of Uncertainty in Paint Analysis

依据GB/T 36488-2018《涂料中多环芳烃的测定》测定涂料中萘含量。通过测量结果不确定度数学模型,分析了不确定度来源因素。评估了测定过程中配制储备液不确定度、标准工作溶液不确定度、曲线拟合不确定度、样品称量质量不确定度、样品定容体积不确定度、萃取过程及上机重复性不确定度分量,最终得到测量结果扩展不确定度。当涂料样品中萘含量的测定结果为146.8 mg/kg时,相对扩展不确定度为(146.8±8.31)mg/kg(k=2)。通过分析不确定度分量,表征实验中增加标准品的纯度、增加标准曲线配制重复测定次数,提高检验的准确性。

The content of naphthalene in paints was determined according to GB/T 36488-2018 Determination of Polycyclic Aromatic Hydrocarbons in Coatings.The uncertainty source factors were analyzed by the mathematical model of uncertainty of measurement results.The uncertainty in the preparation of reserve solution,uncertainty in the standard working solution,uncertainty in the curve fitting,uncertainty in the sample weighing mass,uncertainty in the sample sizing volume,uncertainty in the extraction process and onboard repeatability components were evaluated during the determination process,and the final extended uncertainty of the measurement results(95%confidence interval,extension factor k=2)was obtained.When the determination of naphthalene content in paint samples was 146.8 mg/kg,the relative extended uncertainty was(146.8±8.31)mg/kg(k=2).By characterizing the uncertainty components,the accuracy of the test was improved by increasing the purity of the standards and the number of repeated measurements of the standard curve preparation in the experiment.