Amino Acids And Peptides By Nonaqueous Capillary Electrophoresis Separation

Capillary electrophoresis (CE) is a kind of new chromatography separation analysis technique, which adopts capillary as separation passage and high voltage constant current electrical field as driving force. It has many advantages including high performance, high speed and small sample consumption, and has been widely used in the field of chemistry, biochemistry, life science, medical drugs, environmental science and so forth.As a branch of CE, nonaqueous capillary electrophoresis(NACE) not noly has the advantage of CE, but also has its own unique characteristic and the superiority comparing with the aqueous phase capillary. The research scope is also continuously expanding, and has covered the basic research and the analysis application fields related to the separation of inorganic ion, neutral material, the organic acid, the polypeptide, the polysaccharid, the medicine and its metabolite and so on. At present, however, the physico-chemical properties of very many nonaqueous solutions are not very clear. Moreover, the organic reagent types are various. All of these problems can bring certain difficulty to the choice of reagent. But, they can provide many subjects for the reseacher with reference to the choice rule of the solvent system and the optimized method research in future.Amino acids and dipeptides are important components of life organisms, so the research of their separation by NACE is of great significance on the research in protein, polypeptide, medicine, food, health, and other fields. However amino acids and dipeptides have no or weak ultraviolet absorption and the low contents, so they can not be detected directly by UV detection. At present, the widely used derivatization reagents are o-phthalaldehyde (OPA), 9-fluorenylmethyl chloroformate (FMOC), dansyl chloride(DNS), but these reagents have also been reported some various shortcomings in their application, such as short detection wavelengths, poor stability of reagents and serious interference in the determination of biological samples. In this thesis, two new labeling reagents have been synthesized and applied to the separation of amino acids and dipeptides by nonaqueous capillary electrophoresis. The thesis consists of three chapters.Chapter one:The developments of nonaqueous capillary electrophoresis (NACE) and the applications in Medicine analysis, chiral separation, inorganic ion separation and many other fields have been simply introduced. Moreover, the strategy of the substance searation and the correlation elementary knowledge have been simply elucidated.Chapter two:The separations of Derivatized dipeptides by nonaqueous capillary electrophoresis was investigated.A new method for the separation of dipeptides by NACE using l,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate (BCEOC) as derivatization reagent has been developed. The effect of several key factors on the separation was studied. Under the proposed conditions, a good baseline resolution for 11 derivatized dipeptides was achieved.Chapter three:The separations of amino acids by NACE were investigated. The principal contents of this chapter consist of two parts.3.1 The applications of l,2-benzo-3-4-dihydrocarbazole-9-ethyl chloraformate (BCEOC) for separation of amino acids by NACE are investigated.A simple and rapid method for the separation of derivatized amino acids using 1,2-benzo-3,4-dihydrocarbazole-9-ethyl chloroformate ( BCEOC ) as derivatization reagent by nonaqueous capillary electrophoresis has been for the first time proposed. The effect of the different organic solvent and the different electrolyte on the separation was observed. In addition, The other effect of the proportion of the mixture organic solvent, the concentrations of the electrolyte, separation voltage and temperature was also evaluated in this experimentation.Under the optimal conditions, 14 derivatized amino acids were resolved with a satisfactory result.3.2 The applications of 2-(11 H-benzo[a]carbazol-11-yl) ethyl carbonochloridate (BCEC-C1) for the separation of amino acids by NACE are investigated.A simple and rapid method for the separation of derivatized amino acids using BCEC-C1 as derivatization reagent by NACE has been developed. With the mixed methanol and acetonitrile as the elution solvent, a satisfactory separation for the 11 amino acid derivatives could be obtained when ammonium acetate and acetic acid were used as the electrolyte. The effects of several key factors such as the proportion between MeOH and ACN, the concentrations of ammonium acetate and acetic acid on separation were also evaluated in this experimentation.