甲基橙氧化褪色光度法测定微量碘的研究

Study on the Spectrophotometric Determination of Iodine by Oxidation Decoloration of Methyl Orange

基于硫酸介质中，碘酸根在溴化钾的催化作用下对甲基橙有较好的氧化褪色作用。建立了分光光度法测定微量碘的新方法．最大吸收波长为508nm，表现摩尔吸光系数为3．13×10^4L／（mol·cm），线性范围为在0～50μg／（50mL）。用于食品中碘的测定，获得满意结果。

In the medium of H2 SO4 and catalyzed bypotassium bromide, iodate can oxidize and decolorize methyl orangeery well. The optimum reaction conditions for the spectrophotometric determination of a trace amount of iodine were tbund. The maxium absorbance is at 508 nm, and the linear range is 0 - 50 μg/（50 mL）. The apparent molar absorptivity is 3.13 × 10^4 L/（ mol · cm）. The method has been used in the determination of iodine in foods with satisfactory results.