微波消解-ICP-MS在海洋沉积物国际互校中的应用及不确定度评定

Application of microwave-digestion-ICP-MS determination and uncertainty evaluation in a trace elements intercomparision exercise of marine sediment

应用微波消解-电感耦合等离子体质谱仪(ICP-MS)对国际原子能机构环境实验室(International Atomic Energy Agency Environment Laboratories,IAEA-EL)国际互校样品进行了测定,并对沉积物中样品称量、消解过程、样品定容方式、标准溶液配置、标准曲线拟合等影响样品测定结果的不确定度进行了评定,评定结果表明,沉积物样品消解过程是影响分析准确度的最主要的因素。根据IAEA国际互校样评估报告,除未进行Z-Score评价的元素外,其余元素评定结果均为可接受。

The microwave digestion and ICP-MS was employed for sample pretreatment and elements determination in the marine sediment during the intercomparision exercise organized by IAEA-EL. For evaluating the uncertainty, the factors of sample weighing, digestion procedures, the volume type, the dilution of standard solution, curve fitting and the measurement repeatability was estimated, and the result show that the uncertainty derived from sample digestion procedure was the major factor to affect the accuracy in the trace elements analysis. According to the final evaluation report from IAEA-EL,the results were acceptable based on the Z-score evaluation method, except the elements that Z- score values were not calculated.