镉为一蓄积性中毒成分,某些矿山、工厂和核反应堆的废气和废水中,可能有镉污染,因而研究测镉的方法,对环境保护有一定意义。目前推荐的测镉方法主要有原子吸收法和双硫腙法。前者灵敏度和选择性均佳,但仪器的推广受到一定限制。双硫腙萃取比色法沿用已久,但试剂不够稳定,常用大量氰化钾,虽经改进,手续仍烦。所以进一步探索较好的比色法,无论对例行分析和简易监测似有必要。近来报告过许多噻唑偶氮类型的试剂 Cadmium is an accumulated poisoning component. In some mines, factories and nuclear reactors, there may be cadmium pollution in the exhaust gas and wastewater. Therefore, the study on the method of measuring cadmium has certain significance for environmental protection. Currently recommended methods for measuring cadmium are atomic absorption and dithizone methods. The former sensitivity and selectivity are good, but the promotion of the instrument subject to certain restrictions. Dithizone extraction colorimetry has long been used, but the reagent is not stable enough, a large number of commonly used potassium cyanide, although the improvement, procedures are still annoying. So to further explore the better colorimetric method, both for routine analysis and simple monitoring seems necessary. A number of thiazole azo type reagents have recently been reported