THE POLAROGRAPHIC AND VOLTAMMETRIC DETERMINATION OF N,N-DIMETHYL-4-AMINO-3'-NITROAZOBENZENE

The polarographic reduction of N,N-dimethyl-4-amino-3'-nitroazobenzene was studied hy last polarography and differential pulse polarography, constant potential coulometry and cyclic voltammetry and a mechanism was proposed for the reduction. Optimal conditions were found for the determination of the test substance using tast polarography in the concentration range 1 . 10(-4) - 2 . 10(-6) Mol l-1, differential pulse polarography at a classical dropping mercury electrode and fast scan differential pulse voltammetry at a hanging mercury drop electrode in the range 1 . 10(-4) - 2 . 10(-7) mol l-1 and linear scan voltammetry at a hanging mercury drop electrode in the range 1 . 10(-5) - 2 . 10(-8) mol l-1. A further increase in the sensitivity was achieved through adsorptive accumulation of the test substance on the surface of the working electrode, permitting the determination to be carried out in the concentration range 1 . 10(-7) - 2 . 10(-9) mol l-1.