Separation Of Valsartan On Novel Ion Exchange Type Chiral Stationary Phases And Novel Method Preparing Polyacrylamide-based Chiral Stationary Phases

High performance liquid chromatography (HPLC) represents the most popular and highly applicable technology in the field of chiral analysis and preparation. As the need to obtain individual enantiomer is increasing, exploring new chiral separation materials is still an interesting topic. With regard to the chiral separation of valsartan, the paper involves exploiting two kinds of chiral stationary phases (CSPs). In addition, it also involves developping a new method to prepare polyacrylamide-based CSPs.The CSPs based on QN/QD and L-amino acid derivatives were prepared. The chromatographic results revealed that these CSPs showed good chiral recognition abilities toward valsartan enantiomers with methanol as a mobile phase, and the QN/QD moiety played an important role in the retention of valsartan enantiomers, and that the chiral moiety, L-amino acid derivatives, was dominant in controling the elution order of valsartan enantiomers. These CSPs had great potential in preparative enantioseparations of valsartan.The replacement of QN/QD moiety with imidazolium moiety, we found L-proline derivatives-based imidazolium CSPs affording excellent enantioselectivity for valsartan enantiomers using methanol as mobile phase. Evaluation results of CSPs indicated that the imidazolium moiety was responsible for the retention of valsartan enantiomers and L-proline derivatives moiety took charge of the chiral recognition mechanism. These CSPs had more advantages over those QN/QD-based CSPs in preparative enantioseparations of valsartan due to the ease of obtaining their selectors.The CSP based on the copolymer of (S)-N-(1-phenylethyl)acrylamide and trimethoxysilylpropyl methacrylate was obtained. Chromatographic results stated clearly that the CSP afforded more excellent enantioselectivity for most of the analytes studied than a CSP prepared by the tpical "grafting-to" method. This method could generate more ordered polymeric layer architecture. Furthermore, the polyacrylamide-CSPs based on L-proline and L-leucine derivatives were prepared using the novel method.The results showed that the enantioselectivities of these CSPs were relevant to chiral side chains.