表面活性剂增敏催化分光光度法测定痕量锰

摘要

In the presence of surfactant polyethylene glycol-400（PEG-400）,the color-fading of the dyestuff ＂sunset yellow＂ by oxidation with sodium persulfate was catalyzed by manganese（Ⅱ）,and the stability and speed of the color-fading reaction were obviously enhanced.Based on these facts,a surfactant-sensitized catalytic spectrophotometric method for determination of trace amount of manganese（Ⅱ） was proposed.Linear relationship between the magnitude of decrease in absorbance ΔA and mass concentration of manganese（Ⅱ） was obtained in the range of 0.05-4.0 mg·L-1.Detection limit（3S/N） found was 20 μg·L-1.In the determination of trace of manganese（Ⅱ） in water samples by the proposed method,values of recovery found by standard addition method were in the range from 98.6% to 101.8%,with values of RSD′s（n=5） less than 1.5%.%在表面活性剂聚乙二醇-400（PEG-400）存在下,锰（Ⅱ）对过硫酸钠氧化日落黄（一种染料）的褪色反应具有催化作用,且对此反应的速度及稳定性有明显提高。在此基础上提出了测定锰的催化分光光度法。锰（Ⅱ）的质量浓度在0.05～4.0mg.L-1范围内与ΔA呈线性关系。方法的检出限（3S/N）为20μg.L-1。方法用于水样中痕量锰的测定,并做回收试验,测得回收率在98.6%～101.8%之间,测定值的相对标准偏差（n=5）小于1.5%。