Determination of Trace Cadmium by Catalytic Spectrophotometry

A new discoloring spectrophotometric method for the determination of trace cadmium was established based on the discolor reaction of cadmium to methyl red(MR)in sulfuric acid medium.The linear range and the determination limit for cadmium were 0.02—0.50μg/mL and 6.7×10-3μg/mL,respectively.The RSD was 2.92% and 3.54% and the recovery was 96.0%,103.5%.It is quick and simple with little interference.It can be applied to the determination of trace cadmium in water samples of environment with satisfactory results.