微波消解-石墨炉法测定蔬菜中镍的不确定度评定

Evaluation of Microwave Assisted Digestion-Graphite Furnace Method in Measurement of Uncertainty of Nickels in Vegetables

为了科学合理地表示微波消解-石墨炉法测定蔬菜中镍含量的测定结果 ,根据《测量不确定度评定与表示》JJF1059.1-2012技术规范的要求,以测定卷心菜中镍为例,对测量不确定度进行了评定,分析主要的来源并进行定量,计算相对合成标准不确定度,评定扩展不确定度。结果表明,影响测定结果的主要因素是仪器测量时校准曲线的拟合,用该法测得样品镍含量为0.148 mg/kg,扩展不确定度为0.009 mg/kg(95%,k=2):该评价方法及其结果对在实际的工作中提高测量结果准确性有一定的理论依据。

In order to scientifically and rationally show the measurement results of nickels in vegetables by the microwave assisted digestion-graphite furnace method,the paper evaluates the measurement uncertainty taking the nickels in cabbages according to the JJF1059.1-2012 technical specifications of measurement uncertainty evaluation and expression,analyzes the major source for measurement,calculate the uncertainty of relative synthesis standard and evaluate the expansion uncertainty.The results show that the major influence factors are the fitting of calibration curves in measurement,the nickel content and expansion uncertainty measured by this method were respectively 0.148 mg/kg and 0.009 mg/kg(95%,k=2),and the evaluation method and results have a certain theoretical basis for improving the accuracy of measurement results.