微波消解-原子荧光法测定化妆品中砷含量的不确定度评定

Evaluation of uncertaintyin measurement of Arsenic content in cosmetics by microwave digestion-atomic fluorescence spectrometry

建立微波消解-原子荧光法测定化妆品中砷含量的不确定度评定方法。建立有效的数学模型,对影响测量过程的不确定度来源进行分析和评定。结果表明:当取置信概率为95%,包含因子K=2,该方法测定化妆品中砷含量的扩展不确定度为U=0.222 mg·kg-1,测量结果表示为4.45±0.222 mg·kg-1。校准曲线拟合和测量重复性是影响该方法不确定度的主要因素。

The method of evaluation the uncertainty in measurement of arsenic content in cosmetics by microwave digestion-atomic fluorescence spectrometrywas established. The sources of uncertainty affecting the measurement process were analyzedand evaluated based on an effective mathematical models.Results showed that the uncertainty of expanded uncertainty of arsenic in cosmetics was U = 0. 222 mg·kg^-1and the results were 4. 45± 0. 222 mg·kg^-1when the confidence probability was 95%,comprising a factor K =2. The main factors of the uncertainty were calibration curve fitting and the measurement repeatability.