Determination of medecamycin by adsorptive stripping voltammetry with an activated electrode.
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.
Li
Nian Bing
NB
School of Chemistry and Chemical Engineering, Southwest China Normal University, Chongqing 400715, P.R. China. linb@swnu.edu.cn
Luo
Hong Qun
HQ
Chen
Guo Nan
GN
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
D000900:Anti-Bacterial Agents; D018942:Macrolides; C499507:medecamycin; D002244:Carbon