Application Of Capillary Electrophoresis For Determination Of Active Components In Tea Samples

In the area of analysis science, capillary electrophoresis （CE） has made anothersignificant progress after liquid chromatography，which play an extraordinary role inthe process of analysis and determination of complex samples. In this paper, CE wasapplied to the analysis of amino acids, low molecular organic acids and some vitaminsin tea water samples. Combining with the highly efficient separation of CE, theanalytical methods for some metal and inorganic ions in environmental water sampleswere also developed. This paper aimed to improve the capillary electrophoresismethod and enlarges the application fields. The dissertation consists of eight chapters.In Chapter1， The principium, characteristic and progress capillaryelectrophoresis technology were reviewed. The progress of separation and analysis ofactive components in tea and ion analysis of environmental water by CE werereviewed. The objective and content of this dissertation were described in brief.In Chapter2，Four important amino acids, arginine （Arg）, tryptophane （Trp）,phenylalanine （Phe） and tyrosine （tyr） were simultaneously separated successfully anddetermined by capillary zone electrophoresis （CZE） using direct UV detection. Themethod was applied to the determination of Arg, Trp, Phe and tyr in eleven teasamples with different fermentation tea samples. The results were satisfied. Itprovided some beneficial reference to evaluation quality of tea.In Chapter3，a general method based on capillary zone electrophoresis wasdeveloped for determination lysine（Lys）, proline（Pro）, leucine（Leu）, alanine（Ala）,histidine（His）, Threonine （Thr）, methionine（Met）, serine（Ser）, glycine（Gly） nineamino acids. Acid hydrolysis was used for sample preparation. The method issatisfactory in the measurement of Lys, Pro, Leu, Ala, His, Thr, Met, Ser and Gly inthe manufacturing process of tea products. It indicated that the method is available todetermine amino acids in teas and evaluation for the quality of teas well. In Chapter4，Capillary electrophoresis with direct ultraviolet UV detection forseparation and determination of five organic acids, including ascorbic acid,chlorogenic acid，caffeic acid, protocatechuic acid and gallic acid，were developed.The five organic acids existed in negative ion forms were separated in65mmol/Lborate buffer at pH9.18, separation voltage of20kV and detection wavelength at263nm. The proposed method has been successfully applied for the analysis of spikedChennianpuer tea samples.In Chapter5, a rapid, convenient, sensitive and reproducible capillary zoneelectrophoresis for determination of vitamin B₁, B₂, B₆, C was developed. Theproposed method has been successfully applied for determination of the Biluochun tea.This method may be used in tea, vegetables and other vitamin-rich substances weredetermined.In Chapter6, a rapid, convenient, sensitive and reproducible capillary zoneelectrophoresis for the determine of K⁺, Ca²⁺, Na⁺,Mg²⁺and Zn²⁺five metal cationswas developed. The proposed method has been successfully applied for determinationof the Longjing tea and Baiyan mineral water in real samples.In Chapter7, capillary zone electrophoresis with UV detection at214nm wasdeveloped for the simultaneous determination of phosphate and calcium in waters,The results showed that reasonable resolution with low interference from other ionspresent in the water was achieved. The method was successfully applied to theanalysis of HPO42-and Ca²⁺in waters, which provided a fast and simple procedurethat required no modification of the CE instrument.In Chapter8, capillary zone electrophoresis with UV detection using2,6-pyridinedicarboxylate （PDCA） as the electrolyte was developed for thedetermination of Cr（III）and Cr（Ⅵ）. The proposed method was demonstrated for thedetermination of chromium species in wastewaters.