Study On Capillary Electrophoresis On-Line Preconcentration Technique

In this thesis,the development and application of CE and its on-line preconcentration technique were reviewed.The basic principle and characteristics of Staking and Sweeping were introduced,and the following aspects were investigated.The major content is described as follows:1.A sweeping micellar eletrokinetic capillary chromatographic method has been developed for separation and quantitative analysis of andrographolide and dehydroandrographolide in andrographis paniculata ness.The operating buffer was composed of 20 mmol/L boric acid-10mmol/L sodium didecylsulfate-50 mmol/L SDS containing 20%methanol(V/V)at pH was 2.4,the detection wave-length was 240 nm.Up to 200-fold improvement in multiple of enrichment was achieved by using this sweeping injection technique.The detection limits of andrographolide and dehydroandrographolide are 0.40μg/mL and 0.72μg/mL,respectively.2.A sweeping micellar eletrokinetic capillary chromatographic method has been developed for separation and quantitative analysis of Psoralen and Isopsoraden in Psoralea corylifolia L.The operating buffer was composed of 35 mmol/L disodium tetraborate decahydrate-40 mmol/L SDS containing-5 mmol/Lβ-CD-5 mmol/L Urea-10%ethanol (V/V)at pH 2.4,detection wave-length 246 nm.Up to 160-fold improvement in multiple of enrichment was achieved by using this sweeping injection technique.The detection limits of Psoralen and Isopsoraden are 0.022μg/mL and 0.017μg/mL.3.A new method for the simultaneous determination of Glycyrrhetic acid and Ferulic Acid by stacking-non-aqueous-capillary electrophoresis had been proposed.The operating buffer was composed of 30 mmol/L sodium acetate-2.5 mmol/L sodium hydroxide in methanol.The non-aqueous solvent is methanol and ethionine with the ratio of 4 to 6.The UV detection wavelength was 254 nm.The detection limits of Glycyrrhetic acid and Ferulic Acid are 0.069μg/mL and 0.0 87μg/mL.This method has been successfully used for the determination of Glycyrrhetic acid and Ferulic Acid in Liquorice.4.A new method for the simultaneous determination of emodin,resveratrol and resveratrol-3-O-β-D-glucoside by stacking-non-aqueous-capillary lectrophoresis had been proposed.The operating buffer was composed of 30 mmol/L sodium acetate-4 mmol/L sodium hydroxide-2 mmol/L CTAB in methanol.The UV detection wavelength was 220 nm.This method had been successfully used for the determination of three extracts in Polygoni Cuspidati.