CEPHALOSPORIN ANTIBIOTICS AT CARBON-PASTE AND MODIFIED CARBON-PASTE ELECTRODES IN BOTH AQUEOUS AND BIOLOGICAL MEDIA

A sensitive voltammetric method has been developed for the oxidation a nd determination of the cephalosporin antibiotics Cefatrexyl, Velosef, Claforan, Cefobid and Rocephin at both carbon paste and modified fatt y acid carbon paste electrodes, The electroanalytical technique used w as direct current stripping voltammetry. The adsorptive stripping resp onse was evaluated as a function of preconcentration time, preconcentr ation potential, modifier percentage and other variables. The effect o f the interfering materials such as ascorbic acid, uric acid and some metal ions, i.e. Cu(II) and Fe(III), has also been taken into consider ation. A detection limit down to 10(-8) M has easily been achieved. Ap plication of the method to biological samples (e.g. urine and serum) h as been assessed.