Transport studies of beta-lactam antibiotics and their degradation products across electrified water/oil interface

An electrochemical method for quantifying beta-lactam antibiotics (cephalex in and ampicillin) and their hydrolysis products is described. Cyclic volta mmetry at the water/nitrobenzene interface in a four-electrode system was u sed. The zwitterionic compounds were ionized to the necessary electrochemic al form by pH adjustment. The pH change, however, resulted also in hydrolys is of the antibiotics. Hydrolysis products were characterized across UV-vis spectrum. The various hydrolysis products as well as the ionized antibioti cs were studied in voltammetric transfer from water to nitrobenzene using t he method of the interface between two immiscible electrolyte solutions (IT IES). It was concluded that this electrochemical method is suitable for the quantification of beta-lactam antibiotics and their hydrolysis products. ( C) 1999 Elsevier Science B.V. All rights reserved.