电感耦合等离子体发射光谱法测定土壤中铜、锌含量的不确定度评定

Evaluation and Expression of Determination of Total Copper and Zinc Uncertainty in Soil by Inductively Coupled Plasma Optical Emission Spectrometry

采用电感耦合等离子体发射光谱法对土壤标准物质(GSS-38)中的铜、锌含量进行测定,并对测量结果进行不确定度评定。分析整个检测过程中产生不确定度的来源,发现检测不确定度的来源主要包括样品称量、标准溶液配制、校准工作曲线拟合、试液定容、仪器误差及实验室重复性等分量,并计算了各分量的相对标准不确定度。研究发现测量结果不确定度主要来源于测定溶液定容、标准曲线稀释配制、测量重复性等。采用置信概率为95%,包含因子k=2,电感耦合等离子体光谱法测定土壤中铜含量的测定结果为(176.9±4.8)mg/kg,锌含量的测定结果为(507.8±10.6)mg/kg。

Inductively coupled plasma optical emission spectrometry was used to determine the content of copper and zinc in the soil reference material(GSS-38),and the uncertainty of the measurement results was evaluated.The sources of uncertainty generated in the whole detection process were analyzed.Analyzed the sources of uncertainty in the testing process,including sample weighing,standard solution preparation,calibration curve fitting,test liquid volume and measurement results,calculated the relative standard uncertainty of each component,it was found that the uncertainty of measurement result was most affected by test liquid volume standard curve dilution preparation,measurement repeatability.With a confidence probability of 95%and factor k=2,the results of inductively coupled plasma spectrometry were(176.9±4.8)mg/kg for copper and(507.8±10.6)mg/kg for zinc in soil.