高效液相色谱法测定食品中糖精含量的不确定度分析

目的找出影响仪器分析的测量不确定度的因素,为评估测量结果提供科学依据。方法按照GB/T5009.28方法,用由国家标准物质中心提供的GBW(E)100008标准溶液进行逐级稀释为标准使用液,样品经处理后,用Agilent/DAD高效液相色谱仪测定。结果由影响仪器分析的测量不确定度的因素有5个方面:标准使用液引起的不确定度、样品取样量引起的不确定度、标准峰面积引起的不确定度、样品溶液峰面积引起的不确定度和由样品稀释总体积引起的不确定度。其值分别为0.0075、0.000403、0.00128、0.00427、0.0076。标准合成不确定度为1.50×10-2,扩展不确定度为4.50×10-2。结论影响仪器分析的5个方面因素,对合成标准不确定度贡献最大的标准溶液和样品稀释容器体积允差引起的不确定度,其值分别为0.0075和0.0076。

Analysis of uncertainty of saccharin sodiuln In fooddetected by High performance liquid chromatography

ObjectiveTo find out the influencing factors of uncertainty in instrumental analysis and provide a scientific basis for evaluating measurement results.MethodsUsing the standard solution confected by National Standard Research Center for CRM,the saccharin standard solution was preparated by stepwise dilution method. After Treatment,the samples were detected according to GB/T5009.28 by Agilent/DAD high performance liquid chromatograph instrument. ResultsThe factors which influence uncertainty in instrumental analysis mainly come from five aspects:standard solution,sampling amount,standard peak area,peak area of sample solution,total volume of sample dilution. The uncertainty form the five factors were 0.0075、0.000403、0.00128、0.00427、0.0076 separately. And the results show the combined standard uncertainty was 1.50×10-2,the expanded uncertainty was 4.50×10 -2. ConclusionStandard solution and total volume of sample dilution were the main factors in the five factors to influence combined standard uncertainty. And the uncertainties resulted from the allowable error of the two were 0.0075,0.0076 separately.