Adsorptive properties of cefpodoxime proxetil as a tool for a new method of its determination in urine

It was found that the reduction of the cefpodoxime proxetil (CP) molecule is strongly influenced by the adsorption. The adsorptive properties of CP were investigated in order to achieve an increase sensitivity of its determination. Validated adsorptive stripping differential pulse voltammetry is applied for the determination of low concentration of CP at pH 3.5 and 9.0 where the best pronounced adsorption effects were observed. The linearity of the calibration curves were achieved from 1 x 10(-8) to 1 x 10(-7) M with limit of detection (LOD) of 6.3 x 10(-9) and 7.1 x 10(-9) M, and limit of quantification (LOQ) of 2.1 x 10(-8) and 2.3 x 10(-8) M, at pH 3.5 and 9.0, respectively. The proposed method was tested for CP determination in spiked urine samples, enabling determination of low concentrations of CP. (C) 2004 Elsevier B.V. All rights reserved.