Liquid Chromatography Methods With Electrochemical Detection For The Analysis Of Aminoglycosides

In this work liquid chromatography combined with electrochemical detection method (LC-ED) for direct aminoglycosides (AGs) determination was presented systematically, several ion-pair high performance liquid chromatography methods with pulsed amperometric detection, and several high performance anion-exchange chromatography methods with copper modified electrodes direct current amperometric detection were established mainly. These methods solved the problem to direct determination of AGs.The major part of chapter one comprises a comprehensive review of classification, structure, source of aminoglycosides and current quantitative methodologies for the analysis of aminoglycosides. There are microbiological assay, immunoassays, spectrophotometric and other non-separative methods, thin-layer chromatography (TLC), gas chromatography (GC), capillary electrophoresis (CE), high-performance liquid chromatography (HPLC) separative methods outlined and discussed.In chapter two, the principle, charateristics and current studies on pulsed amperometric detection (PAD) for the analysis of aminoglycosides were introduced. Three new reversed-phase ion-pair LC methods with pulsed amperometric detection were studied. These methods allowed for the simultaneous determination of main component and the possible impurities in etimicin and kanamycin. From the results of the experiments, these methods not only eliminated the requirement for derivatization steps, but also were simple, sensitive, accurate and reproducible, and so, can be used widely.In chapter three, copper chemically modified electrodes (CMEs) were fabricated, and successfully applied to direct current amperometric detection of AGs by high performance anion-exchange chromatography (HPAE-DC) . In contradistinction to bare electrodes, the CMEs extended the electrochemically active windows and changed the catalytic mechanism, the surface absorption passivation was decreased remarkably, the catalytic sensitivity was higher and linear range was wider as well. Without pre- and post-column derivatization, these method can simultaneously determinate the main component and impurities in amikacin and spectinomycin, but also were simple, rapid, sensitive, accurate and reproducible. Ease of preparation, being applied in DC detection mode and good catalytic stability confirmed the interests of applications as electrochemical sensors in other flow-through systems such as capillary electrophoresis and microfluidics.