| The hyphenated technique of high performance liquid chromatography and electrospray ionization mass spectrometry (HPLC-ESI/MS), based on the powerful separating ability of HPLC and high sensitivity and specificity of MS, is widely applied to many fields such as phytochemistry, analytical chemistry, biochemistry, environmental control, clinical medicine and pharmacological researches.The studies in this thesis are included as follows:I The recent progress of supplementary food industry and problems they meet was summarized; the advance in on-line HPLC-MS technique and application of this technique was also reviewed.II Analysis of bioactive components in supplementary food1. An HPLC-ESI/MS method was developed for the simultaneous analysis of theanine, chlorogenic acid, purine alkaloids and catechins in tea samples and tea extracts, based on the high sensitivity, specificity of HPLC-ESI/MS technology. Identification and determination of different compounds can be done made with the multi-information provided by the method. This method can also provide HPLC fingerprints of bio-active components in tea, and can be used to evaluate the quality of tea samples. An isocratic HPLC method was established for the fast determination of theanine in tea and supplementary foods containing tea. This method appears simple, accurate and precise.2. Optimal conditions for separation and purification of theanine form green tea extracts by preparative HPLC were investigated and a production process was established. The technique proposed in this thesis is quite simple and with good recovery, the products obtained by using this technique can be used as high-purity standards provided forquantitative determination of theanine in tea or dietary supplements with tea in it.III Analysis of forbidden drugs in supplementary food 3. A rapid, specific and reproducible HPLC-UV-ESIMS method was developed for the simultaneous determination of sildenafll, vardenafil and tadalafil in sexual potency enhancing foodstuff. This newly developed method has been used for the rapid analysis of sildenafll, vardenafil and tadalafil in supplementary food such as drinks, wine and liquid preparations, the three analytes showed good linearity between peak area and concentrations in the examined ranges, and good recoveries were obtained.4. A HPLC-UV-ESIMS method was established for the determination of orlistat in anti-obesity supplementary food. This developed method has been used for the rapid analysis of orlistat in foodstuff. |
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