电感耦合等离子体发射光谱法测定五氧化二钒中硫、磷、砷、铁含量的不确定度评定

Uncertainty Evaluation of Determination of Sulfur,Phosphorus,Arsenic and Iron Content in Vanadium Pentoxide by Inductively Coupled Plasma Emission Spectroscopy

对电感耦合等离子发射光谱法测定五氧化二钒中硫、磷、砷、铁的不确定度来源进行了详细分析,对测定过程中的主要不确定度进行了合理的评定,包括:样品称量引入的不确定度、校准稀释引入的不确定度、仪器重复测量引入的不确定度,通过建立数学模型,对各不确定分量进行评估量化,计算合成不确定度和扩展不确定度。从各不确定度分量的数据来看,校准溶液稀释和仪器重复测量所引入的不确定度对合成不确定度贡献最大,在日常工作中应重点关注,尽量减小这两种不确定度,确保测量结果更接近真实值。当置信概率为95%,包含因子为2时,样品中硫质量分数为0.012%时,其扩展不确定度为0.002%,磷质量分数为0.008%时,其扩展不确定度为0.002%,砷质量分数为0.007%时,其扩展不确定度为0.002%,铁质量分数为0.35%时,其扩展不确定度为0.03%。

A detailed analysis was conducted on the sources of uncertainty in the determination of sulfur,phosphorus,arsenic,and iron in vanadium pentoxide using inductively coupled plasma emission spectroscopy.The main uncertainties in the determination process were reasonably evaluated,including uncertainties introduced by sample weighing,calibration dilution,and instrument repeated measurements.A mathematical model was established to evaluate and quantify each uncertain component,and the synthetic and extended uncertainties were calculated.From the data of various uncertainty components,it can be seen that the uncertainty introduced by dilution of calibration solution and repeated measurement of instruments contributes the most to the synthesis uncertainty.In daily work,attention should be paid to minimizing these two types of uncertainty as much as possible to ensure that the measurement results are closer to the true values.When the confidence probability is 95%and the inclusion factor is 2,the expanded uncertainty of the sample is 0.002%when the sulfur content is 0.012%,0.002%when the phosphorus content is 0.008%,0.002%when the arsenic content is 0.007%,and 0.03%when the iron content is 0.35%.