示波极谱滴定法测定工业废水中的硫化物

在pH为5.5的醋酸-醋酸钠-氯化钾底液中,用Cu~(2+)离子沉淀硫化物,过量的Cu~(2+)离子用标准8-羟基喹啉溶液回滴,以8-羟基喹啉在单微铂电极示波极谱图上的敏锐切口指示滴定终点。废水的色度、浊度等对测定不产生干扰,无须进行预蒸馏处理,操作简便、快速。方法的相对偏差小于1.0％,变异系数小于0.6％,水样的加标回收 率为97—103％。

Determination of Sulfide in Industrial Waste Water by Oscilloscopic Polarography Titration

Determination of sulfide in industrial waste water by oscilln scopic polarography titration was studied. In acetic acid-sodium acctate-potassium chloride base solution at pH 5.5, S2- can be precipitated with standard solution of Cu2+ and the excess Cu2+ is back titrated with standard solution of oxime. Oxine gives sharp incission in the cell with one P1-micro electrode, which can be used to indicate the end point. The colour and turbidity of the sample do not influence the determination and hence the sample needs no prcdistillation. The process is very simple and rapid. The relative deviation and variation coeffitient are below 1.0% and 0.6%, respectively. The recovery was determined to be 97.0-103%.