库仑滴定法测定食用碘盐中碘酸钾含量  

Determination of potassium iodate in edible iodized salt by coulometric titration

作　　者：张坦 白友强 朱琳[2] ZHANG Tan;BAI Youqiang;ZHU Lin(Qingdao Vocational and Technical College of Hotel Management,Qingdao 266100;Ocean University of China,Qingdao 266003)

机构地区：[1]青岛酒店管理职业技术学院,青岛266100 [2]中国海洋大学,青岛266003

出　　处：《中国食品添加剂》2023年第11期185-189,共5页China Food Additives

摘　　要：建立库仑滴定法测定食用碘盐中碘酸钾的分析方法。以铜电极-铂丝对电极作电解电极对,铜离子选择性电极-饱和甘汞电极作指示电极对,1.0 mol/L氯化钾溶液(pH 3.0)作支持电解质,利用阳极电解生成的Cu^(2+)滴定预处理后样品溶液中剩余的I-至滴定终点后,通过电解时间间接测得样品中碘酸钾含量。该方法的回收率在97.6%~101%之间,相对标准偏差(RSD)低于1.3%。与国标规定的氧化还原滴定法和分光光度法相比,测定结果相近。该分析方法操作简便、检测效率较高,且准确可靠,从而适用于测定食盐中碘酸钾含量。Coulometric titration method in determination of potassium iodate in edible iodized salt was established.The electrolysis electrode pair was copper electrode-platinum,copper ion selective electrode-SCE electrode was the indicating electrode pair;1.0 mol/L potassium chloride solution at pH 3.0 was the supporting electrolyte,the copper ion that anode electrolysis generated titrated surplus iodide ion in sample solution after pretreatment.The content of potassium iodate was indirectly calculated by electrolysis time.The recovery range was 97.6%~101%and RSD was lower than 1.3%.The result was similar to the oxidation-reduction titration and spectrophotometry and coulometric titration which were used in the national standard.The method has the advantages of simple operation,quick analysis speed,accurate and reliable.It is suitable for determination content of potassium iodate in salt.

关 键 词：库仑滴定法 食用碘盐 碘酸钾 铜电极 碘化钾 

分 类 号：TS207.5[轻工技术与工程—食品科学]