电感耦合等离子体-原子发射光谱法测定食品中二氧化钛测定的不确定度评定

目的评定电感耦合等离子体-原子发射光谱法测定食品中二氧化钛含量的不确定度。方法建立电感耦合等离子体-原子发射光谱法测定食品中二氧化钛含量的数学评价模型,对测定过程的主要不确定度进行了合理的评定,主要包括样品称量、样液定容、样液测量以及测量的重复性,将各不确定度分量进行合成,计算合成标准不确定度及扩展不确定度。结果在95%的置信区间下,当样品中二氧化钛含量为54.0 mg/kg时,其测量结果为(54.0±1.4) mg/kg,k=2。结论主要的不确定度来自样品溶液浓度测量和测量的重复性,样品的称量和样液的定容影响较小。在检验过程中,可以通过相关控制措施来减少不确定度。

Uncertainty evaluation for the determination of titanium dioxide in food by inductively coupled plasma-atomic emission spectrometry

Objective To evaluate the uncertainty of the determination of titanium dioxide in food by inductively coupled plasma-atomic emission spectrometry. Methods A mathematical evaluation model for the determination of titanium dioxide in food by inductively coupled plasma-atomic emission spectrometry was established. The main uncertainty of the measurement process was reasonably assessed, including sample weighing, sample volume adjustment, sample liquid measurement, and measurement repeatability. Each uncertainty component was synthesized to calculate synthetic standard uncertainty and extended uncertainty. Results Under the 95% confidence interval, when the titanium dioxide content in the sample was 54.0 mg/kg, the measurement result was (54.0±1.4) mg/kg, k=2. Conclusion The main uncertainty comes from the measurement and repeatability of the concentration of the sample solution. The weighing of the sample and the constant volume of the sample solution have little effect. During the inspection process, relevant control measures can be used to reduce uncertainty.