富硒低钠盐中碘含量的测定

目的探讨富硒低钠加碘盐中碘含量的测定方法。方法通过不同的实验条件,优化国标GB/T13025.7-2012《制盐工业通用试验方法碘的测定》中氧化还原滴定法中的试剂用量,检测出富硒低钠加碘盐中的碘含量。结果改变碘化钾溶液量、淀粉溶液量、磷酸-草酸溶液量均无法测定富硒低钠盐中的碘含量;只有当次氯酸钠溶液用量≥5mL时,加入碘化钾溶液,才可以使富硒低钠加碘盐溶液显色,然后通过实验确定次氯酸钠的最佳用量,再滴定测定碘含量。结论富硒低钠加碘盐中含有还原性物质,测定其碘含量需加大次氯酸钠溶液的用量。

Determination of iodine content in rich-selenium and low-sodium salt

Objective To discuss the determination method of iodine content in rich-selenium and low-sodium iodized salt. Methods Through different experimental conditions, the amount of the Redox titration reagent used in GB/T 13025.7-2012 Determination of iodine in the general test method for salt production industry was optimized to detect the iodine content in rich-selenium and low-sodium iodized salt. Results When changing the amount of potassium iodide solution, starch solution measure, phosphoric acid-oxalic acid solution, the iodine content in selenium-rich and low-sodium salt could not be determined. Only when the amount of sodium hypochlorite solution was not less than 5 mL, the potassium iodide solution could be added to make the selenium-enriched low-sodium iodized salt solution develop color, and then the optimal amount of sodium hypochlorite was determined experimentally, and the iodine content was determined by titration. Conclusion Reducing agents is contained in selenium-rich low-sodium iodized salt, determination of the iodine content need to increase the amount of sodium hypochlorite solution.