ICP-OES法测定燃香类产品中Cr元素的不确定度评定

采用ICP-OES法对燃香类产品中Cr元素含量进行测定，依据JJF 1059-1999《测量不确定度评定与表示》，建立数学模型，对ICP-OES法测定燃香类产品中Cr元素的不确定度评定产生的来源进行识别，对不确定度的分量进行计算、合成与评估，得出Cr元素在一定浓度范围内的不确定度。测得样品中W（Cr）=56.7mg/kg，W（Cr）测定结果的扩展不确定度为U=2mg/kg，K=2。结果表明，计量器具的精度和标准曲线的拟合对不确定度的影响较大，实际工作中可通过定期对仪器和计量器具进行校准与检定，来减少对不确定度的影响。通过测量不确定度的评定，掌握ICP-OES法测定燃香类产品中Cr元素含量结果的准确性，从而保证检测工作的质量。

Uncertainty evaluation of chromium content in incense by ICP-OES

In this paper,the chromium content in incense was determinated by ICP-OES,the mathematical model was established according to JJF1059-1999 "Evaluation and Expression of Uncertainty in Measurement".The causes of uncertainty to determination of the Chromium content in incense by ICP-OES were identified,every components of the uncertainty was calculated,and the uncertainty result within a certain range of chromium element concentrations was calculated.The result was W(Cr)=56.7mg/kg,and U=2mg/kg,K=2.The result showed that accuracy of measuring instrument and standard curve fitting both have great effect on uncertainty.In practice,their effects on uncertainty can be reduced by regularly calibrating and verifying instruments and meters.The evaluation of uncertainty can obtain the accuracy of results of determination of the chromium element in incense by ICP-OES,and assure the detection quality.