Ionization Regulation Of API-MS And Application Studies On LC-MS Hyphenated Technique In The Metabolism Of Drugs And Endogenous Substances

Atmospheric pressure ionization (API) is a type of soft ionization technique. API including ESI and APCI provides efficient ionization for very different molecules including polar, labile, and high molecular mass drugs and metabolites. Recently, the API-MS has been successfully hyphenated with HPLC, this kind of technique is used widely in drugs, metabolites, and endogenous substances, which makes trace analysis of the composition of medicinal samples become possible. This technique provides a universal mean of monitoring for the compounds without chromophore. Today, HPLC-MS has been a commomly-used technique because of the rapid development in the instrumentation.HPLC-MS is now extending its applications from the field of natural medicine product, pharmacokinetics, screening drugs and the analysis of complex drug to the biological macromolecule and biological science. The development of analytical method depends on the ability in separation of chromatography and detection of mass spectrometry. At the same time, the development of HPLC-MS will be promoted by the application in the detection, screening and identification of target drug and the analysis of unknown metabolite. The aim of the thesis is to explorer the ionization regulation of different type compound in APCI and ESI. As the main research tool, several LC-MS analytical methods have been established. The pharmacokinetics of glimbenclamide in clinical patient was first investigated. Then, the study of bioequivalence of telmisartan was carried out. The method for determination of relative and absolute bioavailability of azithromycin was also developed in this thesis. Finally, the concentration of 25-hydrroxy-vitamin D3 in plasma is...