废水中二氧化硫脲的分光光度法测定

本文提出了分光光度法测定二氧化硫脲的新方法。在ｐＨ１１．３的碱性介质中，二氧化硫脲可将芳香族硝基化合物还原为芳香族伯胺，经重氮化后与萘乙二胺反应生成红色的偶氮染料。其最大吸收波长为５２５ｎｍ，线性范围为２．０￣４０．０ｍｇ／Ｌ，检测限２ｍｇ／Ｌ，回收率９７．０％￣１０２．７％。本法灵敏度高，对二氧化硫脲有较好的选择性，用于为水中微量二氧化硫脲的测定，结果满意。

Spectrophotometric Determination of Thiourea Dioxide in Waste Water

A novel spectrophotometric method for the determination of thiourea dioxide (TD) was proposed. In the alkaline medium of pH 11. 3, thiourea dioxide can reduce aromatic nitro compounds to primary aromatic amines and the latters form red azo dyes with N- (1-naphthyl )ethylenediamine dihydrochloride after diazotization with a maximum absorption at 525 nm. The calibration graph is linear for 2. 0~40. 0 mg/L TD, the detection limit is 2 mg/L, and the recovery is 97. 0%~ 102. 7%. The method is sensitive and selective. The thiourea dioxide content in waste water has been determined with satisfactory results.