| The pharmaceutical analysis plays a major role in assuring safety, effcacy, purity, andquality of a drug product. The science and technology utilized today have madepharmaceutical analysis methods much more accurate and precise. Electroanalyticaltechniques, as a novel analytic method for pharmaceutical analysis, are of particularadvantage because of their practicality, simplicity, low-cost, good sensitivity, precision andrapidity for real-time detection. Recently, the application of various nano-carbon materialmodified electrodes in the pharmaceutical analysis has been made great progress. Mesoporouscarbon is a kind of novel advanced carbon material, which performs many good characteristic,such as large pore volume, high specific surface area, tunable pore size distribution andchemical inertness. The electrodes modified with mesoporous carbon exhibit excellentlyelectrochemical activity for various electroactive compounds. In this work, two kinds ofmesoporous carbon were employed as electrode modified materials for electrochemicalstudies and quantitative examination of some drug molecules. The major contents aredescribed as follows:1. An electrochemical sensor based on ordered mesoporous carbon （OMC） for theamperometric detection of isoniazid was developed. OMC was dispersed in a solution ofNafion, and the suspension was modified onto the surface of glassy carbon （GC） electrode.Cyclic voltammetry and amperometry were used to investigate the electrochemical behaviorsof isoniazid on Nafion-OMC modified electrode （Nafion-OMC/GC）. The results indicate thatOMC can facilitate the electrochemical oxidation of isoniazid with a great decrease ofoverpotential in pH7.0phosphate buffer solution. The proposed biosensor provides excellentperformance towards the determination of isoniazid with a high sensitivity of0.031A/M, alow detection limit of8.4×10-8M and wide linear range from1.0×10-7M to3.7×10-4M at+0.20V versus Ag/AgCl. The method was successfully applied to the determination ofisoniazid tablets with satisfying results. All the results suggest that Nafion-OMC/GC electrodeis a potential candidate for a stable and efficient electrochemical sensor to detect isoniazid.2. A cobalt hexacyanoferrate/large-mesopore carbon modifed glassy carbon electrode（CoHCF-LMC/GC） was simply fabricated by electrodepositing CoHCF film on LMC bycyclic voltammetry （CV）. The electrochemical behaviors of L-dopa at this modified electrodehave been studied by CV, differential pulse voltammetry （DPV） and amperometry. The resultsshow that the CoHCF-LMC modifed electrode exhibits efficiently electrochemical activityfor the oxidation of L-dopa in0.1M PBS （pH=7.4）, and the oxidation is unperturbed by theascorbic acid （AA）. Amperometry results depict that the proposed sensor provides excellent performance towards the determination of L-dopa with a low detection limit of1.7×10-8M inthe wide concentration range from1.0×10-7to1.9×10-3M at+0.20V versus Ag/AgCl.Moreover, the studied composite electrode exhibits a good reproducibility and long-termstability. Determination of L-dopa in commercial tablets and human blood serum withsatisfying results was also investigated by the proposed composite electrode. |
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