Electrochemical reduction of cefminox at the mercury electrode and its voltammetric determination in urine.
The electrochemical behaviour of cefminox in phosphate buffers solutions over pH range 2.0-9.0 using differential-pulse polarography, DC-tast polarography, cyclic voltammetry and linear sweep voltammetry (staircase) has been studied. In acidic media, a non reversible diffusion-controlled reduction involving two electrons occurs and the mechanism for the reduction was suggested. A differential-pulse polarographic method for the determination of cefminox in the concentration range 5.8x10(-6)-6.0x10(-5) M with a detection limit of 1.76x10(-6) M was proposed. Also, a method based on controlled adsorptive pre-concentration of cefminox on the hanging mercury drop electrode followed by linear sweep voltammetry, allows its determination in the concentration range 8.3x10(-8)-1.5x10(-6) M with a detection limit of 2.47x10(-8) M. These methods have been used for the direct determination of cefminox in human urine with recoveries between 98 and 103%, and precision around +/-2%.
Hilali
Abdelilah
A
Department of Analytical Chemistry, Faculty of Chemistry, Universidad de Sevilla, Professor Gracia Gonzalez 19, 41012 Seville, Spain.
Jiménez
Juan Carlos
JC
Callejón
Manuel
M
Bello
Miguel Angel
MA
Guiraúm
Alfonso
A