title: Determination of medecamycin by adsorptive stripping voltammetry with an activated electrode.
abstract: The adsorptive and electrochemical behaviors of medecamycin were investigated on a glassy carbon electrode (GCE) pretreated by anodic oxidation at +1.8 V for 5 min in 0.025 mol l(-1) NH(3)-NH(4)Cl (pH 8.6) solution. An adsorptive stripping voltammetric method for the determination of medecamycin at the pretreated glassy carbon electrode has been developed. Medecamycin was accumulated in NH(3)-NH(4)Cl buffer (pH 9.0) at a potential of -0.7 V (vs. saturated calomel electrode (SCE)) for a certain time, and then determined by second-order differential anodic stripping voltammetry. The second-order differential anodic stripping peak current at +0.72 V was proportional to the concentration of medecamycin in the range 2.0 microg ml(-1) to 50.0 microg ml(-1). The detection limit (three times the signal-to-noise) was 1.0 microg ml(-1) and the relative standard deviation of the results was 3.28% for eight successive determinations of 10.0 microg ml(-1) medecamycin. This method has been applied to the direct determination of medecamycin in commercial tablets and spiked urine samples with satisfactory results.
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest China Normal University, Chongqing 400715, P.R. China. linb@swnu.edu.cn
authors.forename: Nian Bing
authors.initials: NB
authors.lastname: Li
authors.forename: Hong Qun
authors.initials: HQ
authors.lastname: Luo
authors.forename: Guo Nan
authors.initials: GN
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D000900:Anti-Bacterial Agents / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D018942:Macrolides / Q000032:analysis*; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; C499507:medecamycin; D002244:Carbon