微量金标准物质定值均匀性检验

Homogeneity test for valuing standard substance of trace gold

利用王水溶样，活性炭吸附－灰化－王水溶解－硫脲提取－原子吸收光谱法测定微量金标准物质（GAu－9b）的30个子样含量，每个子样重复测定3次。分析了天平称量精度、玻璃器皿刻度精度和活性炭吸附率造成的测量不确定度，估算出合成不确定度范围为1．6％～2．2％（A级品），论证了分析测定方法的可行性；对单个样品重复分析结果的可靠性及样品的均匀性进行评估，计算出样品均匀性质量参数为0．77，样品测定结果的相对偏差（RD）均符合地质实验室质量管理规范要求，依此判定该样品的均匀性质量等级为合格。

30 sub-samples of the standard substance of trace gold GAu -9b（ unvalued standard sample）are meas- ured by the process of aqua regia dissolution, activated carbon adsorption - ashing - the aqua regia dissolution - thiourea extraction - AAS,and each sample measured for 3 times. The measurement uncertainty range is estimated to be 1. 6 % to 2.2 % （ Grade A） after the analysis of the weighing accuracy of the balance, the scale accuracy of glass wares and the measurement uncertainty caused by activated carbon adsorption, proving the feasibility of the method; Evaluation on the credibility of repeated assaying results of each sample and the homogeneity is carried out, the quality parameter of homogeneity is 0.77,the RD of the measurement result is consistent with quality management standard re- quirements of geolabs,thus the homogeneity quality is thought to be acceptable.