盐酸联苯胺分离——酸碱滴定法测定实验室废水中硫酸根研究

提出了利用盐酸联苯胺沉淀分离,酸碱滴定法快速测定实验室废水中SO4^2-含量的新方法。在水样消解并掩蔽干扰后的微酸性溶液中,加入的盐酸联苯胺能与SO4^2-作用生成硫酸联苯胺沉淀,沉淀过滤并溶于热水后,以酚酞作指示剂,用NaOH标准溶液滴定至终点。结果表明,改进后的方法操作简单、测定快捷、干扰小、准确度和精密度与标准法一致,测定结果的相对偏差仅为0.36%（n=5）。

Study on the Determination of Sulfate in Laboratory Waste Water by Benzidine Hydrochloride Separate and Acid-Base Titration

A new method is used for the rapid determination of SOn^2- in laboratory waste water by benzidine hydrochloride separate and acid-base titration. After sample of water is dissolved and masking disturbs, in weak acids solution, a reaction of benzidine hydrochloride with SO4^2- will produce benzidine sulfate sediment. This sediment is filter and dissolved with hot water. Then titration by the standard solution of NaOH to end point, with the phenolphthalein as the indicator. The results show that the improved method is an easy-operating way with the fast determination and it is less disturbed. The accuracy and precision of this method accord with those of standard method,and the relative deviation is only 0.36%.