氢化物原子荧光光谱法测定拐枣中硒含量的不确定度评定

Evaluation of Uncertainty on Determination of Selenium Contents in Hovenia Dulcisby Hydride Generation Atomic Fluorescence Spectrometry

从样品称量、标准物质、标准曲线拟合、斜率和截距、标准溶液稀释、回收率、定容和重复性试验等方面对氢化物原子荧光光谱法测定拐枣中硒含量的不确定度进行评定。结果表明,工作曲线拟合引入的不确定度、斜率和截距引入的不确定度和重复性试验引入的不确定度是影响测定结果不确定度的主要因素,而样品称量引入的不确定度较小。由本试验方法得到的拐枣中硒含量扩展不确定度及最终结果表示为(0.0614±0.0090)mg/kg(k=2)。

Uncertainty on determination of selenium contents in hovenia dulcis was evaluated, in the aspects of weighing, standard solution, standard curve, slope and intercept,dilution of stock standard solution, recovery, metered volume and retesting. The result showed that the principaluncertainty on determination of selenium contents of this method comes from standard curve fitting, slope and intercept, retesting, while sample weighing revealed little effect on the final uncertainty.The final result of selenium contents in hovenia dulcis measured in this way was expressed as：（0.0614±0.009）mg/kg（k=2）.