甲酚红氧化褪色光度法测定微量碘

Spectrophotometric Determination of Iodine by Oxidation-Decoloration of Cresol Red

本文研究了在硫酸介质中 ,碘酸根在 KBr催化作用下氧化甲酚红使其褪色的最佳条件 ,建立了测定微量碘的新方法。最大吸收波长为 5 19.5 nm,表观摩尔吸光系数为 4 .6× 10 4L· mol-1· cm-1,碘酸根测定线性范围为 10— 6 0 μg/2 5 m L。用于测定食盐和碘酸钾片剂中微量碘 。

A new method has been developed for determination of the micro amounts of iodine by oxidation decoloration with cresol red.The complex has a maximum absorption at 519.5nm in H 2SO 4 (pH0.55-0.75) with a molar absorptivity of 4.6×10 4L·mol -1 ·cm -1 .Beer's law is obeyed for 10-60μg/25mL of iodine.Good results have been achieved in determining iodine in salt and potassium iodine tablets.