ICP-AES法测定金饰品中铜、铁、锌含量的不确定度评定

采用湿法消解样品, 建立电感耦合等离子体发射光谱（ICP-AES）测定黄金饰品中铜、铁和锌元素含量的方法。该方法具有简便、快速、灵敏度高及重现性好等优点。根据测量原理，建立了该方法的定量数学模型并推导出不确定度计算公式，找出了该检测过程中的不确定度来源，对各不确定度分量进行了合成和扩展，得到了铜、铁和锌质量分数的不确定度。结果表明：标准溶液的配制、标准曲线拟合线性方程及重复测量是不确定度的主要来源，黄金饰品中铜、铁和锌的质量分数可分别表示为（10.42±1.54）、（10.79± 1.21）和（26.89±1.88） mg/kg。

Evaluation of Uncertainty in Measurement of Copper, Iron and Zinc in Golden Jewelry by ICP-AES Method

Using wet digestion sample,a method was developed for determination of copper,iron and zinc elements in golden jewelry by ICP-AES method.The method has the advantages of accurate,simple,sensitive and rapid. Based on the measuring principle, the calculation formula was deduced, some data were collected in the procedure of analyzing the golden sample and the various uncertainties in measurement were calculated.According to the international general method,the component uncertainties were synthesized and extended,respectively to obtain the uncertainty evaluation.The results showed that the sources of uncertainty were comprised of sample weighing, the preparation of standard solutions, the fitted linear regression equation for the calibration curve and the repeated determination of copper, iron and zinc concentration in golden jewelry decomposed solution.The combined standard uncertainty and expanded uncertainty of copper,iron and zinc concentration were showed （10.42±1.54）, （ 10.79±1.21） and （26.89±1.88） mg/kg respectively.