摘要
The electrochemical behavior of the degradation product of cefdinir（CDR） was studied in a 0.05 mol/L NaOH solution by means of linear sweep voltammetry（LSV） and cyclic voltammetry（CV）. The results indicate that the C=N bond in the oxime group was reduced. Moreover, a saturated adsorption amount of 1.32× 10^-10 mol/cm2 at Hg electrode was obtained. The adsorption coefficient β was 1.56× 10^5 L/mol. Gibbs standard energy of adsorption AGO at 25 ℃ was -29.63 kJ/mol and the number of electrons transferred n was 2. A method for the determination of CDR was proposed by differential pulse voltammetry（DPV）. The reduction peak currents of the CDR＇s degradation product were found to be linear in a concentration range of 4.0×10^-7--4.0×10^- 6 mol/L and that of 4.0× 10^-8-4.0× 10^-7 mol/L, respectively. The detection limit was found to be 3.0× 10^-8 mol/L under the optimized conditions. The applica- bility of this approach was illustrated by the determination of CDR in capsules. In addition, the mechanism about the degradation of CDR in 0.2 mol/L NaOH was discussed by UV spectrophotometry.
The electrochemical behavior of the degradation product of cefdinir（CDR） was studied in a 0.05 mol/L NaOH solution by means of linear sweep voltammetry（LSV） and cyclic voltammetry（CV）. The results indicate that the C=N bond in the oxime group was reduced. Moreover, a saturated adsorption amount of 1.32× 10^-10 mol/cm2 at Hg electrode was obtained. The adsorption coefficient β was 1.56× 10^5 L/mol. Gibbs standard energy of adsorption AGO at 25 ℃ was -29.63 kJ/mol and the number of electrons transferred n was 2. A method for the determination of CDR was proposed by differential pulse voltammetry（DPV）. The reduction peak currents of the CDR＇s degradation product were found to be linear in a concentration range of 4.0×10^-7--4.0×10^- 6 mol/L and that of 4.0× 10^-8-4.0× 10^-7 mol/L, respectively. The detection limit was found to be 3.0× 10^-8 mol/L under the optimized conditions. The applica- bility of this approach was illustrated by the determination of CDR in capsules. In addition, the mechanism about the degradation of CDR in 0.2 mol/L NaOH was discussed by UV spectrophotometry.
基金
Supported by the Natural Science Foundation of Shaanxi Province in China(No.2005B28)
