碘量法测定食品添加剂硫酸铜主含量的关键技术研究  

Study on the key technology of determination of the main content of food additive copper sulfate by iodometry

作　　者：侯超 王胜杰 张益萍 马跃龙[1] HOU Chao;WANG Shengjie;ZHANG Yiping;MA Yuelong(Shanghai Institute of Quality Inspection and Technical Research,National Food Quality Supervision and Inspection Center,Shanghai 200233)

机构地区：[1]上海市质量监督检验技术研究院,国家食品质量监督检验中心,上海200233

出　　处：《中国食品添加剂》2022年第6期172-175,共4页China Food Additives

基　　金：食品安全国家标准项目(食品添加剂硫酸铜,项目编号:spaq-2020-03)。

摘　　要：目的:对碘量法测定硫酸铜含量关键技术进行探讨,给出合适的淀粉和硫氰酸钾溶液加入点。方法:碘量法测定硫酸铜含量是最常见的方法,参照GB 34459—2017饲料添加剂硫酸铜含量测定方法,探讨淀粉和硫氰酸钾溶液的合适加入点。结果:通过碘量法测定硫酸铜含量,并对关键技术进行探讨,给出了合适的淀粉加入点,即消耗硫代硫酸钠体积约为硫酸铜含量的60%时,硫氰酸钾溶液的合适加入点为消耗硫代硫酸钠体积约为硫酸铜含量的90%时,通过不同实验人员对改进方法进行验证,结果保持一致,不同实验人员结果最大绝对偏差为0.19%,符合标准测定要求。结论:在合适的时间点加入淀粉和硫氰酸钾溶液,可准确测定食品添加剂硫酸铜主含量,精密性和重复性良好,是测定食品添加剂硫酸铜主含量的有效方法。Objective:To explore the key technology for the determination of copper sulfate by iodometry,and to give the appropriate addition point of starch and potassium thiocyanate solution.Methods:Iodometry is the most common method to determine the content of copper sulfate.According to the determination method of copper sulfate in feed additives(GB 34459-2017),the appropriate addition point of starch and potassium thiocyanate solution was discussed.Results:The key technology for the determination of copper sulfate content by iodometry was discussed,and the appropriate addition point of starch was given,that was,when the volume of sodium thiosulfate consumed was about 60%of the CuSO4 content,and the appropriate addition point of potassium thiocyanate solution was at the point of time,when the volume of sodium thiosulfate consumed was about 90%of the CuSO4 content.The improved method was verified by different experimental personnel,and the results were consistent.The maximum absolute deviation of the results of different experimenters is 0.19%,which meets the requirements of standard determination.Conclusion:Adding starch and potassium thiocyanate solution at an appropriate time point can achieve accurate titration for the determination of the main content of copper sulfate in food additives,with good precision and repeatability.It is an effective method for the determination of the main content of copper sulfate in food additives.

关 键 词：碘量法 硫酸铜 关键技术 合适加入点 

分 类 号：TS207.3[轻工技术与工程—食品科学] TS202.3[轻工技术与工程—食品科学与工程]