电感耦合等离子体质谱法测定荷花花粉和油菜花粉中镉含量的不确定度评定

Evaluation of the measurement uncertainty for determination of cadmium in 2 kinds of bee pollens (lotus pollen & rape pollen) by inductively coupled plasma mass spectrometry

中文关键词:  荷花花粉  油菜花粉  电感耦合等离子体质谱法  不确定度  镉

英文关键词:lotus pollen  rape pollen  inductively coupled plasma-mass spectrometry  uncertainty  cadmium

中文摘要:

      目的 评定荷花花粉和油菜花粉样品中镉含量可能产生的不确定度, 以提高测量结果的准确性。方法 采用NexIon 350X型电感耦合等离子体质谱仪对2种蜂花粉中镉的含量进行测定, 建立实验过程的数学模型, 对主要影响测量不确定度的样品称量、标准溶液的配制、标准曲线的拟合、测量的重复性等因素进行分析, 并对各不确定度分量、合成标准不确定度以及扩展不确定度进行计算。结果 荷花花粉中镉含量测定结果不确定度为: U=(0.166±0.010) mg/kg, k=2; 油菜花粉中镉含量测定结果不确定度为: U=(0.0599±0.0033) mg/kg, k=2。 结论 影响测定荷花花粉和油菜花粉中镉含量的不确定度的主要来源为标准溶液稀释和样品重复性试验。电感耦合等离子体质谱法测定荷花花粉和油菜花粉中镉含量是可靠的。

英文摘要:

      Objective To assess the uncertainty of cadmium content in lotus pollen and rape pollen samples, in order to improve the accuracy of the measurement results. Methods The analysis of uncertainty evaluations for determination of cadmium in 2 kinds of bee pollens was carried on NexIon 350X ICP-MS. The mathematical model of uncertainty evaluation was established. The major sources which affect uncertainty evaluations were attributed, such as sample weighing, standard solution preparation, calibration curve fitting, and repeatability of measurement. Finally, combined standard uncertainty as well as expanded uncertainty was calculated. Results The uncertainty of determination of cadmium content in 2 kinds of bee pollens were (0.166±0.010) mg/kg (k=2) in lotus pollen and (0.0599±0.0033) mg/kg (k=2) in rape pollen, respectively. Conclusion The most important factors of uncertainty for determination of cadmium in 2 kinds of bee pollens are standard solution dilution and sample repeatability tests. Inductively coupled plasma mass spectrometry is reliable for determination of the cadmium in 2 kinds of bee pollens.