直接沉淀滴定法检测鱿鱼丝中氯化钠的 不确定度评定

Uncertainty evaluation for determination of sodium chloride in squid shreds by direct precipitation titering method

中文关键词:  直接沉淀滴定法  不确定度评定  氯化钠

英文关键词:direct precipitation titering method  uncertainty evaluation  sodium chloride

中文摘要:

      目的 对直接沉淀滴定法测定鱿鱼丝中氯化钠的含量进行不确定度评定。方法 对氯化钠含量测定过程中各影响因素包括称量、样品溶液定容、测定试液体积、标准滴定溶液浓度、滴定过程等进行分析评定。结果 鱿鱼丝中氯化钠检测的不确定度主要由标准滴定溶液浓度的不确定度分量和重复性试验误差引入, 而标准滴定溶液浓度的不确定度分量贡献最大。通过对标准溶液浓度的不确定度评定, 发现其主要不确定度由称量过程中的不确定度引入。该方法检测鱿鱼丝中氯化钠的扩展不确定度为0.043%。本实验测定的氯化钠含量结果为(2.49±0.043)%(P=95%, k=2)。结论 本方法可为评定食品中氯化钠含量的测量结果和方法的可靠性提供科学依据。

英文摘要:

      Objective To evaluate the uncertainty of determination of sodium chloride in squid shreds by direct precipitation titering method. Methods The uncertainty caused by various factors in the whole process of determination was analyzed, including weighing, solution preparation, solution delivery, standard titration solution concentration and titration process, etc. Results The uncertainty of the method was mainly caused by the uncertainty of concentration of titrating solution and repetitive error, especially the uncertainty of concentration of titrating solution derived from weighing process. The expanded uncertainty was 0.043%. The content of sodium chloride in squid shreds was (2.49±0.043)%(P=95%, k=2). Conclusion The established method can provide basis for evaluation of the reliability of the measurement method and results of sodium chloride in food.