原子荧光法测定罐头食品中锡含量的不确定度评定

Uncertainty analysis of tin in canned food with atomic fluorescence spectrometry

评估罐头食品中锡含量测定的不确定度,分析测量过程中存在的不确定度来源。结果表明,引起测量不确定度的主要因素是测定C值时用最小二乘法拟合标准溶液浓度-荧光强度曲线、标准溶液配制和测量重复性所带来的不确定度;求出合成不确定度和扩展不确定度,分析结果为X=(5.74±0.25)mg/kg,k=2,置信概率95%,该方法适用于罐头食品中锡含量测定的不确定度评估。

The uncertainty of tin in canned food during the measurement was analyzed.The major source of the uncertainty was determination of ’C’,including the calibration curve calculated on the basis of the principle of method of least squares,the standard solution preparation and repeatability of measurement.The combined uncertainty and expanded uncertainty were finally obtained.The analysis result was X=（5.74±0.25）mg/kg,k=2,the confidence probability 95%.This method was suitable for evaluating the uncertainty of tin in canned food.