Colour Reaction of Chromogenic Reagent 2-Pyridinediazoaminoazobenzene With Cadmium(Ⅱ) and Its Application
Wang Chaocun, Ha Chengyong (Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650)
The synthesis of a new reagent 2 - pyridinediazobenzene and its chromogenic reaction with cadmium(Ⅱ) ion was reported. In a weak alkaline medium, the reagent reacts with cadmium(Ⅱ) to form a red complex of component ratio 4: l(R: Cd). The absorption maximum of the complex is at 530 nm and the apparent molar absorptivity is 1 .92 ×105 L. mol-1. cm-1. Beers law is obeyed for cadmium (Ⅱ ) in the range of 0-0.5 mg/L. This method has been employed to determine trace amount of cadmium(Ⅱ ) in waste water with satisfactory results.
【CateGory Index】： O657.3