原子荧光法测定大蒜中硒含量的不确定度评定

Uncertainty Evaluation of Selenium Content in Garlic Powder by Atomic Fluorescence Spectrophotometry

采用微波消解-氢化物发生原子荧光光谱法测定大蒜中硒的含量,并对测定结果进行不确定度评定.通过标准溶液配制、工作曲线拟合、样品制备过程、样品重复性测定等分量的不确定度评估,得出本方法的不确定度主要来源于样品制备过程和重复性测定.所测定的大蒜粉样品中硒的平均含量为0.404 mg/kg,扩展不确定度为0.048 mg/kg(k=2).

Content of selenium in garlic powder was determined by hydride generation atomic fluorescence spectrophotometry(HGAFS)assisted with microwave digestion.Analysis and calculation of uncertainty were carried out according to Evaluation and Expression of Uncertainty in Measurement.Major sources of uncertainty came from sample preparation and repeatability.When selenium content in garlic powder is 0.404 mg/kg,the expanded uncertainty is 0.048 mg/kg(k=2).