Preparation And Application Of Novel Amino Acid Derivative Chiral Stationary Phases

Enantioseparation is a continuously challenging task. The method of high performance liquid chromatography chiral stationary phases(HPLC-CSPs) is fast, accurate and will not disrupt the structural and biological activity of enantiomers, which is widely used in agriculture, biology and so on. The research and development on the HPLC-CSPs has always been the critical study. In recent years, cyanuric chloride(CC) has gradually used in the preparation of chromatographic fillers. It can react with-OH and-NH2 because the three chlorine atoms have highly reactive, and chlorine atoms of CC can be replaced by controlling the temperature, so different derivatives and chiral stationary phases were prepared.We select L-valine and L-alanine acids as chiral selector,pH was adjusted 8 with appropriate NaHCO3 solution,the temperature was controlled 0-10 °C, 25 °C and 80 °C, respectively,a series of amino acid derivatives substituted cyanuric chloride were prepared: One substituted triazine derivative(mole ratio of cyanuric chloride and amino acid is 1 : 1.2), two substituted triazine derivative(mole ratio of one substituted triazine derivative and amino acid is 1 : 1.2), three substituted triazine derivative(mole ratio of cyanuric chloride and amino acid is 1 : 3.2) and mixed substituted triazine derivatives(mole ratio of one substituted triazine derivative and amino acid is 1 : 1.2), and the obtained products were characterized. Two L-p-toluoyl amino acid CSPs were prepared by reaction of amino acids with p-toluoyl chloride. The obtained derivatives were characterized by IR spectrum. The immobilized-type chiral stationary phases were prepared by bonding the obtained derivatives onto the surface of the aminopropyl silica gel.The obtained eight CSPs were evaluated using the mixture of hexane-isopropyl 95/5(V/V) as a mobile phase in HPLC, six chiral compounds were achieved different separation. Meanwhile, the influence of composition in mobile phase was also discussed on CSP-6. The three positional isomers of nitrophenol were separated on the obtained CSPs, the results were compared with the result of C18 column.Two L-p-toluoyl amino acid CSPs were prepared and evaluated, the influence of different mobile phase compositions on chiral separation of 3 racemates was also discussed. Results showed that racemates 1-3 achieved baseline separation and partially separation on the CSPs.Moreover, enantioseparations were achieved for thirteen chiral etheric compounds under the normal phase mode using Chiralcel OD-H, Chiralpak AD-H and Chiralcel OJ-H chiral columns. The results showed that the separations for the most compounds were completed in shorter analysis time, this maybe relation with the difference of the hydrogen bonding interactions between analytes and CSPs.