碘离子选择电极法直接分析微量碘酸钾

Direct Analysis of Trace Potassium Iodate by Iodium Ion-selective Electrode

碘酸钾是一种广泛用于加碘食品、营养品和补碘制剂的微量有效成分。文章介绍一种采用碘离子选择电极和饱和甘汞电极直接恻定微量碘酸钾含量的电化学分析法。在由0.01mol／LKNO3和0．09mol／LVc组成的混合介质中，碘酸钾的标准曲线在1．610－7mol／L～1．010－2mol／L范围内是线性的，检测下限为0．034μg／ml。用于含碘酸钾颗粒剂分析，其相对标准偏差和回收率分别为8．5％（n＝8）和105．2％。

Potassium iodate (KIO3) is a kind of trace effective composition widely used inthe iodate foods, nutriments and replenishing iodium preparations. A electrochemical analyticalmethod is presented, with which the content of trace potassium iodate was directly measured byan ion-selective electrode and a saturated calomel electrode. In the mixed medium composed of0.01 mol/L KNO3 and 0. 09 mol/L Vc, the calibration curve for KIO3 was linear in the 1 .6 ×10-7mol/L - 1. 0×10- 2 mol/L, and the detecting lower limit of KIO3 was 0. 034 μg/ml. Therelative standard deviation and recovery of analysing the granule containing potassium iodate withthe method were 8. 5 % (n = 8) and 105. 2 %, respectively.