ICP-AES法测定Pt950首饰中Pd含量的不确定度评定

Uncertainty Evaluation of Pd in Pt950 Jewelry Analyzed by ICP-AES

目前中国贵金属珠宝检测实验室在贵金属检测测量不确定度评定及应用方面尚不成熟,各实验室建立系统的不确定度评定显得极为重要。选取贵金属检测常用的ICP-AES法,以测量PT 950首饰中Pd含量为例,通过建立不确定度数学模型,分析确定测量不确定度影响因素,最终计算得到测量结果的扩展不确定度为44.02‰±0.326 8‰。通过结果分析发现,影响结果测量不确定度主要来源于标准溶液配制及工作曲线拟合、样品重复性检测,其相对不确定度分别为0.003 4和0.001 3,而质量和体积引入的不确定度可以忽略不计。通过示例的不确定度评定不仅提高检测结果可信度及完整性,也为国内各珠宝实验室完善不确定度评定程序提供参考。

It is quite important to evaluate measurement uncertainty during the precious metal testing. However, evaluation and application of uncertainty in most domestic precious metal testing lab are immature nowadays. In this paper, the measurement uncertainty was evalua-ted by determination the percentage of Pd in Pt950 jewelry by means of inductively-coupled plasma atomic emission spectrometry （ICP-AES）. The authors established a mathematic model, and analyzed various factors. The result showed that the expanded uncertainty was calculated to be 44. 02 %〇 ＋ 0. 326 8 %〇 finally. The uncertainty mainly came from the stand-ard solution preparation and measurement of calibration curve which resulted in uncertainty of 0. 003 4 ,and from the sample repeatability tests resulted in uncertainty of 0. 001 3 , and the influence of mass and volume were very small. This study not only aims at improving the re-liability and integrity of the test results, but also aims at providing references for the im-provement of the uncertainty evaluation program in domestic gem and metal testing lab by giving an illustrative demonstration.