R&um&Le comportement tlectrochlmlque de la mltoxantrone $ 1'Ckctrode de mercure a ete etudk en technique chronocoulomktnque en falsant appel aux mtthodes polarographlques conventionnelle et lmpulslonnelle La vague polarographlque bklectromque enregstrte est reversible et son potenhel de demo-vague amsl que son mtensltk dependent du pH Les mesures de capaclte d'tlectrode mettent en tvldence l'adsorptlon des formes oxydte et redmte de la mltoxantrone i la surface du m&al A pH = 1 et en technique lmpulstonnelle (mtkgratlon des courants de 1 B 41 ms apres le saut de potentd) la vague prmclpale est smvle d'une vague totalement dlssymetrlque qm resulte de la rkductlon du film adsorb& au potentlel mltlal Cette dermere vague est contr6lee par un processus de nuclkatlon et crolssance hdlmenslonnelle Mats clefs mltoxantrone, mercure, reolutlon, adsorption Abstract-The electrochemical behavior of mltoxantrone at the mercury electrode has been studied chronocoulometrlcally usmg direct and pulse polarographlc techniques The recorded two-electron wave IS reversible and both its half-wave potential and its mtensrty depend on pH Electrode capacity measurements demonstrate the adsorption of both the oxidized and the reduced forms of rmtoxantrone
Usmg the pulse method at pH 1 (current integration from 1 to 41 ms), the mam wave IS followed by a dlssymmetncal wave resultmg from the reduction of the film adsorbed at the mltlal potential This last wave IS controlled by a nucleation and bldlmenslonal growth process