Study Of Hydrogen Bonding Effect Of Hydroxy Acid Buffer On Capillary Zone Electrophoresis Separation

Selecting hydroxy acid (lactic acid, Malic acid, tartaric acid, citric acid) salt as a buffer system of high performance capillary zone electrophoresis, according to the possible different forces from the formation of all hydrogen bonds betweet objects such as nicotine nornicotine, myosmine, anabasine, DNA, amino acids, amino acid isomers and alcholic acid, a series separation studies were completed. The separation conditions such as buffer pH, alkyd concentration, electrophoresis run voltage, and sample injection lengh andelectrophoresis run temperature were investigated. The optimal conditions were applied in different appications successfully. The main results and innovation points are as follows:(1) While concerning whether the hydrogen bond between the buffer and the separated object exist or not, an important similar complex formed by hydrogen bond between tobacco biological alkaloid myosmine cation and citric anion are found,which mantaining stable separation behavior of myosmine in CZE. Basing on the principle, myosmine can be analyzed successfully.(2) Tobacco alkaloids were separated on baseline by capillary zone electrophoresis with a buffer solution of pH3.2,360mmol/L tartaric acid. Cation-selective exhaustive injection, as an on-column preconcentration method, was also investigated for the determination of the alkaloids of cigarette samples.With the proposed method, both the resolution and detection limit of the alkaloids were improved comparing with those in phosphate buffer.(3)Using chiral purity hydroxy acid salt as buffer system, through their hydrogen bonds stereo selective, the separation of amino acid chiral isomers were accomplished with the help of stereo selective hydrogen bonds interaction. The method peoposed a new strategy for the separation of chiral isomers.(4) Because hydroxy acid salt can bond to DNA, which is rich in lonely pair electronics, the longer the DNA molecular chain, the more the hydrogen bond between hydroxy acid salt and DNA forms, so more resistance DNA receives, more slowly the DNA move towards to detect window, then DNA fragments separate out one by one according to the length of DNA. The experiments demonstrated the interation. separation of DNA Marker was completed successfully using citric acid salt as buffer system.(5) Basing on DNA transient entanglement coupling and improvement of mechanisms of sieve theory in the non-cross-linked polymer solution under high electric field intensity, especially the intra-molecular hydrogen-bonding interaction between DNA and buffer solution, fully utilizing the principle of the separation of DNA:when DNA molecules migrating, DNA fragments tangling or colliding with buffer solution molecules, the larger the DNA,the more the amount of buffer solution molecules encountered and tangled, leading the lower mobility, so separated on the size of DNA fragment. Citrate buffer solution, as a buffer and screening media, was applied to separate single-strand DNA by high performance capillary zone electrophoresis, the analytical method was high precision and good reproducibility.