Application of Adsorptive Stripping Voltammetry for the Determination of Selected Methoxyimino Cephalosporins in Urine Samples

Abstract

In the last two decades different electroanalytical methods were used for sensitive and selective determination of cephalosporins. The paper was focused on the electrochemical behavior of methoxyimino cephalosporins, reduction mechanism and nature of the process at the mercury electrode surface. Special attention was paid to the cephalosporins adsorption at the mercury surface. Based on this phenomenon, the adsorptive stripping methods were established for determination of the low concentration of these drugs in urine samples, both in vitro, and in vivo conditions. The application of Adsorptive Stripping Differential Pulse Voltammetry (AdSDPV) for the determination of cefpodoxime proxetil (CP), cefotaxime (CF), desacetylcefotaxime (DCF) and cefetamet (CEF) was summarized. The best sensitivity of in vitro determination in urine was achieved for CP, in acid solutions (LOD 7.4.10(-9) M and LOQ 2.4.10(-8) M), followed by CF, CEF and DCF. This is in accordance with the strength of their adsorption. Determination of CF and DCF by AdSDPV in vivo was also presented. Compared to other analytical methods, AdSDPV showed advantages in the simplicity of sample preparation, and over the other voltamperometric methods, higher sensitivity and selectivity.