POLAROGRAPHIC-DETERMINATION OF 4'-SUBSTITUTED DERIVATIVES OF 3-CARBOXY-4-HYDROXY-6-ACETYLAMINOAZOBENZENE

Tast polarography, differential pulse polarography and cyclic voltamme try were applied to the examination of 7 derivatives of 3-carboxy-4-hy droxy-6-acetylaminoazobenzene with H, CH3, OCH3, Cl, COCH3, NO2 and NH COCH3 substituents in position 4'. A general reduction mechanism was s uggested for the substances. The half-wave potentials obtained from ta st polarographic measurements were correlated with the Hammett a const ants of the substituents in the para-position. The plot of this depend ence is linear, which suggests that the reduction mechanism is identic al within the entire series. The optimum conditions for quantitation o f the substances were found within the concentration regions of 1 . 10 (-4) to 1 . 10(-6) mol l(-1) for tast polarography and 1 . 10(-4) to 1 . 10(-7) mol l(-1) for differential pulse polarography.