| Capillary electrophoresis (CE), also known as high performance capillary electrophoresis (HPCE), is an analytical technology developing rapidly in recent years. CE has been used widely in the field of food, pharmaceutics, life sciences and environmental monitoring sciences, etc. This thesis is focused on developing simple, rapid, sensitive, reliable qualitative and quantitive methods for the quality control of some Chinese traditional medicine by capillary electrophoresis techniques. The thesis consists of two parts, as described below:Part one Application of MEEKC for determination of some component in Tripterygium wilfordii Hook. f.Chapter1:A novel method of microemulsion electrokinetic chromatography (MEEKC) was established for the determination of triptolide and triptonide simultaneously. In the study, the effect of type and concentration of surfactant, cosurfactant, oil phrase and buffer pH were investigated systematically on the separation. The optimized microemulsion was composed of1%(w/v) sodium dodecyl sulfate,3%(v/v) n-butanol,1%(v/v) ethyl acetate and96%(v/v)5mM borax-10mM phosphate-sodium at pH8.5. With a voltage of25kV, detection wavelength of214nm, column temperature of25℃, injection pressure0.5psi (6s), triptolide and triptonide achieved a good separation within10min, good linear relationship respectively were in0.35~45μg/mL and0.40~26μg/mL, LOD respectively were0.22μg/mL and0.36μg/mL at S/N=3. The results showed, in the crude slices, the content of triptolide was2.0085μg/g, triptonide was14.1490μg/g. In the water boiled slices, triptolide was3.5753μg/g, triptonide was24.5800μg/g. In the tripterygium glycosides tablet, triptolide was11.9655μg/g, triptonide was11.7451μg/g. The high recovery was82.99%-113.94%. The proposed method was proved to be stable and reliable, could be successfully applied to the determination of herbal medicines and the preparations in Tripterygium wilfordii Hook. f.Chapter2:A sensitive and reliable MEEKC method combined with Large volume sample stacking (LVSS) for the analysis of five kinds sesqueteerpenoid alkaloids was developed. The influence of the composition of microemulsion system was investigated, and the optimal separation electrolyte was0.5%(w/v) SDS,3%(v/v) butyl alcohol,0.5%(v/v) n-hexane,3%(v/v) ethanol,7%(v/v) acetonitrile,5mM borax-lOmM sodium dihydrogen phosphate(v/v)86.5%(pH8.5). Under this condition, Peritassine A, Triptonine B, wilfordine, wilforgine, wilforine can be well separated. LVSS was used to improve the sensitivity, the stacking condition was injection time of29.5s, injection pressure of3psi, stacking voltage of-25kV, running voltage of25kV. The results showed that, good linearity was in0.05μ.g/mL~0.80μg/mL, high precision, enrichment factor was13.44-51.07. The method was successfully applied to the analysis of tripterygium wilfordii root bark extracts, the mean recovery of alkaloids was90.65%~106.76%. The MEEKC would provide a novel method for the analysis of Tripterygium alkaloids.Part two Application of MEKC for enantioseparation of some traditional Chinese medicineChapter1:An novel method of micellar electrokinetic capillary chromatography (MEKC) was established to enantioseparated hesperidin and naringin simultaneously. The back-ground electolyte (BGE) consisted of an aqueous solution of20mM NaH2PO4-100mM NaOH buffer (pH9.0), The chiral additive buffer solutions were prepared by dissolved60mM sodium cholate,25mM Hydroxypropyl-β-cyclodextrin,3%methanol(v/v) into the BGE, instrument conditions for separation of a voltage of25kV, detection wavelength of214nm, column temperature of25℃, injection pressure0.5psi (8s). The results showed enantiomers were realized effective separation within10min, high efficiency and good linear relationship were obtained. The lowest detectable limit(LOD, S/N=3) of Hesperidin enantiomers were0.13μg/mL and0.25μg/mL, naringin enantiomers were0.14μg/mL and0.07μg/mL. The method can be successfully applied to the determination of Hesperidin and Naringin enantiomers in a preparation of Weisu granules, the satisfactory recoveries were86.00%~113.20%.Chapter2:A new method was established for the enantioseparation of dl-tetrahydropalmatine by MEKC combined with acetonitrile-field amplified sample stacking technology for online enrichment. In the running buffer of10mM phosphate (pH7.5), with20mM sodium taurocholate as surfacant, at a voltage of25kV, detection wavelength of214nm, column temperature of25℃, injection pressure0.5psi (6s), the enantiomers of d-tetrahydropalmatine and ι-tetrahydropalmatine were baseline separated within10min, the resolution was almost2.96.The effect of online enrichment was good, and was thousands of percent. The method significantly improved the detection sensitivity, and was promising to be used for the microdetermination of d-tetrahydropalmatine.In this paper, the MEEKC and MEKC methods were proved to be stable and reliable, fast analysis of several Chinese medicines, and better separation in the compounds with similar structures., high recovery was obtained in actual samples, so the methods have some value in the practical study. |
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