原子荧光法测定金矿中砷和铋的不确定度评估  

Evaluation of Uncertainty in Measurement of Arsenic and Bismuth in Gold Ore by Atomic Fluorescence Spectrometry

作　　者：张晨芳 刘献锋[2] 

机构地区：[1]有色金属华东地质勘查局,江苏南京210007 [2]南京工程学院环境学院,江苏南京211167

出　　处：《分析测试技术与仪器》2014年第4期243-248,共6页Analysis and Testing Technology and Instruments

摘　　要：通过建立数学模型,分析了原子荧光法测定金矿中砷和铋的测量不确定度的影响因素,计算各影响因素的不确定度分量,并计算金矿中砷和铋的合成标准不确定度和扩展不确定度.结果表明:测量不确定度主要由样品制备过程和标准曲线拟合构成.金矿中砷的含量为18.398μg/g,其扩展不确定度为0.555 3μg/g(k=2),结果符合测试规范要求.铋的含量为0.359 3μg/g,扩展不确定度为0.441 1μg/g(k=2),铋的不确定度偏大,不符合测试规范要求,应通过降低铋标准溶液的浓度和减少待测液的稀释倍数来降低标准曲线拟合产生的不确定度.Through establishing an mathematical model, the evaluation of the measurement uncertainty of arsenic and bismuth in gold ore by atomic fluorescence spectrometry （ AFS） was investigated. Each partial uncertainty of measurement was analyzed and calculated. The combined standard uncertainty and the expanded uncertainty of arsenic and bismuth were calculated respectively. The uncertainty of As and Bi was mainly composed of the uncertainty of the preparation of samples and uncertainty of the fitting of the standard curve. When the concentration of As in gold ore is 18. 398 μg/g, the expanded uncertainty is 0. 5553 μg/g （k=2）. When the concentration of Bi is 0. 3593μg/g, the expanded uncertainty is 0. 4411 μg/g （k=2）. The expanded uncertainty of Bi is too great to satisfy the requirement of measurement standard. In order to reduce the uncertainty produced by the standard curve fitting, it is necessary to prepare a low concentration of standard solution and increase the mount of samples and reduce the dilution ratio of samples.

关 键 词：不确定度 砷 铋 原子荧光法 金矿石 

分 类 号：O657.31[理学—分析化学]