Abstract

This paper uses diphenyl carbazide (DPC) dissolved in water with NaCl, which solves the problem that DPC must be dissolved in organic solvents. At the same time, instead of the phosphoric acid medium used normally in the Chinese National Standard Method (GB7467-87), sulfamic acid was made into a solid mixed chromogenic agent. A standard colourimetric board was made and photographed after the screening for chromium (VI) concentration. The standard colourimetric board and the solid mixed chromogenic reagents and other instruments were assembled into the reagent bottles as the reagent kit for rapid determination of chromium (VI).This article examined the impact of the coexisting ions Fe3+, Mo6+, Ni2+, Cu2+ and Ca2+ on the chromium (VI) determination with the reagent bottles and determined the composition of the solid mixed chromogenic agent and tested the chromium (VI) optimal concentration and the upper limit of coexisting ions permitted amount. The reagent kit was applied to the actual wastewater and evaluated as well.