靛蓝胭脂红褪色光度法测定痕量铈

Fading Spectrophotometry Determination of Trace Cerium with Indigo Carmine

在硫酸介质中,Ce(Ⅳ)对靛蓝胭脂红有褪色作用,并且与存在的Ce(Ⅳ)量在一定范围内呈线性关系,由此建立了分光光度法测定铈的新方法。褪色体系的最大吸收波长为610nm,表观摩尔吸光系数为2.72×103 L/mol/cm,方法的线性范围为0.2～7.8μg/mL,检出限为7.2×10-3μg/mL。该方法简单、快速、准确、选择性好,线性范围宽,用于测定水样中的微量铈,结果满意。

A new method by fading spectrophotometry for the determination of trace cerium （Ⅳ） was developed. The discoloration of indigo carmine by cerium （Ⅳ） in sulfuric acid solution has been studied. The result indicated that decrease in absorbance is proportional to the amount of cerium （Ⅳ）. The maximum absorption is at 610 nm. Its molar absorptivity is 2.72 ×10^-3L·mol-1·cm-1. The detection limit is 7.2 ×10^-3μg · mL-1 . The liner range of the determination is 0.2 - 7.8μg · mL-1. The method was simple, sensitive, accurate and selective. It has been used for the determination of cerium in water sample with satisfactory results.