罗丹明B氧化褪色光度法测定微量碘

Spectrophotometric Determination of Iodine by Oxidation-Decoloration of Rhodamine B

本文研究了在硫酸介质中 ,碘酸根在 KBr催化作用下氧化罗丹明 B使其褪色的最佳条件 ,建立了测定微量碘的新方法。通过实验 ,测得最大吸收波长为 4 90 nm ;表观摩尔吸光系数为 1 .5× 1 0 4 L· mol-1· cm-1;碘酸根测定的线性范围为 0— 3 0μg/1 0 m L;检出限为 1 .2× 1 0 -7mol/L。

A new method has been developed for the determination of the trace of iodine by oxidation-decoloration with rhodamine B.The color system has a maximum absorption at 490nm in the medium of sulfuric acid with a molar absorptivity of 1.5×10 4L·mol -1·cm -1.Beer's law is obeyed in the range of 0-30μg/10mL of iodate.The detection limit is 1.2×10 -7mol/L.The method can be used for determination of the trace iodine in the salts.