DIFFERENTIAL PULSE VOLTAMMETRIC DETERMINATION OF 3,3＇ 5,5＇-TETRAMETHYLBENZIDINE AND ITS ANALOGUES WITH A GLASSY CARBON ELECTRODE

The differential pulse voltarametric ( DPV ) method with a glassy carbon electrode was used for the determination of 3,3‘ 5,5‘-tetramethy lbenzidine ( TMB ) , o-tolidine and benzidine in the acidic media. The pulse amplitude, interval time and scan rate of DPV are optimized to be 50 mV, 0.5 s and 10 mV/s, respectively, The peak current is proportional to the concentration of TMB and its analogues, the linear range is from 10^-8mol/l to 10^-4 mal/l, The electrochemical behaviour of the compounds is discussed, The chemical poisons can be determined directly, or indirectly by the extraction in the waste water of chemical industry and laboratory,