Original scientific paper

Adsorption Effects in Polarography of Berberine

Šebojka Komorsky-Lovrić ; Faculty of Pharmacy and Biochemistry, University of Zagreb, 41000 Zagreb, Yugoslavia
Zvonimir Gašparec ; Faculty of Pharmacy and Biochemistry, University of Zagreb, 41000 Zagreb, Yugoslavia
Marko Branica ; Center for Marine Research Zagreb, »Rudjer Bošković" Institute, POB. 1016, Zagreb 41001, Yugoslavia

Abstract

Adsorption effects in square-wave and d. c. polarography of
berberine are investigated in the supporting electrolytes of various
pH. Tensametric a. c. and SW polarographic measurements show
that both berberine and canadine are strongly adsorbed in the
potential range between -0.3 V and --'1.7 V vs. SCE. The reduction
of berberine proceeds from the adsorbed state and requires four
electrons. The coefficients ana = 1.32 and D = (4.0 ± 0.5) . 10-6 cm2/s are evaluated. There are two kind of faradaic SW responses: the first is associated with very low surface coverage while the second
appears when the surface is totally covered by the adsorbed berberine. In d. c. polarography a pseudo-prewave and pseudo-
-main wave appear.·If pH > 6 the limiting currents of d. c. polarographic waves are severely depressed.

Keywords

Hrčak ID:

176390

URI

https://hrcak.srce.hr/176390

Publication date:

23.12.1987.

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