硫酸锌返滴定法测定磷酸二氢钙含量的测量不确定度评定

目的 对硫酸锌返滴定法测定食品添加剂磷酸二氢钙含量的测量不确定度进行评定, 确保检测结果准确可靠。方法 按照测量不确定度评定的通用规则, 建立了数学模型, 分析了方法中的不确定度分量及其来源, 计算了各分量的不确定度, 最后计算出了检测结果的合成标准不确定度和扩展不确定度。结果 扩展不确定度为0.10%, K=2。结论 标准溶液产生的相对标准不确定度及用硫酸锌溶液滴定产生的不确定度是硫酸锌返滴定法测定食品添加剂磷酸二氢钙含量的主要影响因素。

Evaluation of the measurement uncertainty for the determination of calcium dihydrogen phosphate using back titration analysis of zinc sulfate

Objective The uncertainty of the detection results of calcium dihydrogen phosphate using back titration analysis of zinc sulfate has been evaluated, which ensure the detection results accurate and reliable. Methods According to general rule of evaluation of the measurement uncertainty, mathematical model was established and the measurement uncertainty for the determination of calcium dihydrogen phosphate using back titration analysis of zinc sulfate was analysed. Finally, combined standard uncertainty and the extended uncertainty of detection results were calculated. Results The extended uncertainty was 0.10% (K=2). Conclusion Relative standard uncertainty caused by standard solution and uncertainty caused by titration analysis of zinc sulfate were the main factors for the determination of calcium dihydrogen phosphate using back titration analysis of zinc sulfate.