中性红褪色光度法测定微量铈

Color-fading photometric determination of trace cerium with neutral red

依据在硫酸介质中,微量Ce（IV）的强氧化性能使中性红褪色的原理,建立了一种新型快速测定微量Ce（IV）的褪色光度法。实验结果表明：在530nm处,Ce（IV）浓度在0.5~20.0μg·m L-1范围内与中性红褪色程度ΔA成正比,线性回归方程为：y=0.0165x-0.0084,相关系数r=0.9920,检出限为0.26μg·m L-1。将该法用于稀土矿石中微量铈的测定,分析结果的相对标准偏差为2.7%,加标回收率为98.9%,结果令人满意。

A new fading spectrophotometry method for the rapid determination of trace Ce （IV） was proposed based on the oxidation of neutral red by Ce（IV） in sulfuric acid medium. The experimental results showed that the maximum absorption wavelength of neutral red was 530 nm and do not have any change when it was oxidated by Ce（IV）, in the range of 0.5~20.0μg·m L-1 the reduced absorbance value of the solution was directly proportional to the concentration of Ce（IV）. The linear regression equation of the method was y=0.0165x-0.0084 and the correlation coefficient was 0.9920, the detection limit of the method was 0.26μg·m L-1. This method was applied to determine of trace cerium in rare earth mineral, the result showed that the RSD was 2.7% and the recovery was in rage of 98.9%.