Spectrophotometric Determination of Trace Copper with Methyl Orange-Potassium Bromate

Using the catalytic action on methyl orange-potassium bromate system by copper,a new method to determine the trace copper was established,and then the method was applied to determine copper in the sample. Methods: Spectrophotometric was used for the experiment,the single factor method was used to determine the optimum conditions for the catalytic reaction,the standard addition method and the parallel recovery experiment were applied to determine the accuracy and precision. Results: The maximum absorption wavelength was 508nm; The concentration and dosage of methyl orange were 0. 0002mol / L and 5. 00ml; The concentration and dosage of potassium bromate were 0. 005mol / L and 0. 50ml; The concentration and dosage of nitric acid were 2mol / L and 2. 00ml; The reaction time should be 15min when the temperature was 50℃. The linear range varied from 0. 2mg / L to 16mg /L,the linear equation was ΔA = 0. 0508 +0. 0664c,the correlation coefficient was 0. 9979; The relative standard deviation was 1.3%; The recovery for the sample was 97. 5% ~ 112. 8%.