火焰原子吸收分光光度法测定化妆品中总镉的含量的测量不确定度评定

Evaluation of Measurement Uncertainty in Determination of Total Cadmium in Cosmetics by Flame Atomic Absorption Spectrophotometry

采用微波消解法处理样品、火焰原子吸收分光光度法测定化妆品中总镉的含量,并根据《JJF 1059.1-2012测量不确定度评定与表示》建立数学模型,对上述方法的不确定度进行分析评定。经计算,其测量不确定度主要来源于标准曲线拟合及测量重复性,而称样及稀释过程引入的不确定度则较小;因此,为降低不确定度,提高结果准确性,需定期对仪器进行检定,以保证仪器处于稳定良好的状态。

The samples were treated by microwave digestion and the content of total cadmium in cosmetics was determined by flame atomic absorption spectrophotometry.A mathematical model was established according to JJF 1059.1-2012 Evaluation and Expression of Uncertainty in Measurement,the uncertainty of the above methods was analyzed and evaluated.The uncertainty of measurement was mainly derived from the fitting and measurement repeatability of standard curve,while the uncertainty introduced in the weighing sample and dilution process was smaller.Therefore,in order to reduce the uncertainty and improve the accuracy of the results,the instrument should be confirmed regularly to ensure the instrument was in a stable and good state.