Study Of New Capillary Electrophoresis Methods Based On Ionic Liquids

The study of separation and determination effective components of Chinese herbs was very active to the analyst. But the complicated composites and different collection season and area of Chinese drugs make their analysis become very difficulty. Ionic liquids as the novel separated medium (additives) in the capillary electrophoresis display unique separation and analysis character will greatly help the investigation of Chinese herbs. This dissertation focused on the character of ionic liquids and its application in the analysis Chinese herbs and combined the project of National Natural Scientific Foundation of China (Study on the super high performance capillary electrophoresis based on ionic liquids, grant No. 20275014) and the conditions of our experiments to study the ionic liquids in the capillary electrophoresis from the methods and techniques. On the basis of the previous literatures, in this dissertation, some original studies are carried out as followings:1. Based on the unique separated character of ionic liquids, a novel capillary electrophoresis method on ionic liquids and p-cyclodextrin as running electrolytes for separation and determination of anthraquinones extract of Chinese herb Paedicalyx attopevensis Pierre ex Pitard was developed for the first time.2. Based on high thermal conductivity of ionic liquids, they were used as the additives in capillary electrophoresis and a new method that high electric field strengths apply to the capillary electrophoresis was developed for the first time.3. Two new nonaqueous capillary electrophoresis methods used trishydroxy-methylaminomethane were developed and they were used for the analysis bioactive triterpenes and flavone derivatives in Chinese herbs extraction.This dissertation consists of three parts and seven chapters.Part I Review of the development of capillary electrophoresis based on ionic liquidsIn chapter 1, the physical and chemical character of ionic liquids (ILs) and itsapplication in the capillary electrophoresis (CE) was reviewed and discussed in detail.Part II The study of aqueous capillary electrophoresis based on ionic liquidsIn chapter 2, a method of ionic liquid used as running electrolyte in capillary zone electrophoresis with p-cyclodextrin (P-CD) as modifier for the separation of anthraquinones extract of Chinese herb Paedicalyx attopevensis Pierre ex Pitardwas developed for the first time. The optimum running electrolyte was 60 mM l-butyl-3-methylimizoliurn tetrafluoroborate (1B-3MI-TFB) solution with 4.0 mM p-CD. The pH was 10.00 and the applied voltage was 20 kV with detection at 254 nm.In chapter 3, a very simple capillary electrophoretic method for analyzing aconitine components in Aconitum plants was developed. The optimum buffer system was 35 mM 1B-3MI-TFB solution (pH 8.50). The applied voltage was 15 kV. Aconitine, meaconitine and hypaconitine in Aconitum plants were separated and identified within 5 min.In chapter 4, novel capillary electrophoresis methods used ionic liquids (1E-3MI-TFB, 1B-3MI-TFB) were established to separate and determine some bioactive flavone derivatives in Chinese herb seriphidium santolinum (Schrenk) Poljak. Borate was also used as electrolyte to compare with them. The advantage of CE used ionic liquids as electrolytes for separation was shown. The analysis time was short, the system used ionic liquids was robust because the joule heating was small and the method of CE used ionic liquids has lower detection limits than that of borate.In chapter 5, an aqueous capillary electrophoresis method for the separation and determination of flavone and coumarins in Sinacalia tangutica.v/as developed based on high electric field strengths and ILs. The ionic liquids 1E-3MI-TFB and 1B-3MI-TFB were used as modifiers to improve the separation efficiency and selectivity. The analysis time was short and did not induce excessive Joule heating inthe capillary.Part III the study of nonaqueous capillary electrophoresisIn chapter 6, nonaqueous capillary electrophoresis (NACE) was described for the separation and determination of bioactive flavone derivatives in Chinese herbs extraction. A reliable separation of four analytes in an acetonitrile (ACN): methanol (60:40, v/v) mixture containing 80 mM Tris and 10 mM sodium cholate (SC) was obtained.hi chapter 7, three bioactive triterpenes ursolic acid, oleanolic acid and 2a,3p, 24-trihydroxy-urs-12-en-28-oic acid were simultaneously separated by NACE with methanol:ACN (65:35, v/v) mixture containing 90 mM Tris at an applied voltage of 25 kV. The method was applied to separation and determination the three components in six Chinese herbs extraction.