A novel bonded stationary phase for chiral ligand exchange-chromatography

A novel chiral bonded stationary phase (CBSP) for ligand exchange chromatography was prepared by bonding (S)-1,2,3,4-tetrahydro-3-isoquinoline carboxylic acid prepared from L-Phe to YWG-80 silica gel via 3-glycidyloxypropyltrimethoxysilane as a coupling agent. Chromatographic resolutions of some DL-amino acids were achieved on the CBSP by using an aqueous solution of 2 mmol/L N (C2H5)(3), 2 mmol/L HAc and 0.2 mmol/L Cu(Ac)(2) as the mobile phase with a flow rate 1.0 mL/min, column temperature 50 degreesC and detection at 254 nm. The enantioselectivity a of the DL-amino acids on the CBSP was found to be between 1.11 and 1.51. The elution order of D-isomer before L-isomer on the CBSP was observed for all the DL-amino acids resolved except DL-Val. For DL-Pro, DL-Val and DL-Leu the elution order through the CBSP was different from that through the chiral ligand exchange phases prepared from L-Pro or L-hydroxyl proline with a five-membered ring structure.