Comparative Liquid Chromatographic Enantiomer Resolution on Two Chiral Stationary Phases Derived from Amylose Tris(3,5-dimethylphenylcarbamate)

Polysaccharide-derived chiral stationary phases (CSPs) are known to show high chiral recognition ability in HPLC and have been extensively used to separate a broad range of racemic compounds. 1-3 These type CSPs are usually prepared coating or adsorbing the polysaccharide derivatives on silica gel. Therefore, the solvents such as chloroform, methylene chloride, and tetrahydrofuran which dissolve or swell the chiral selectors of the polysaccharide derivatives cannot be used as mobile phases. 4 For example, in case of Chiralpak AD prepared by coating amylose tris(3,5-dimethylphenylcarbamate) derivative, one of the widely used polysaccharide type CSPs, suitable mobile phases like hexane, 2-propanol and ethanol should be used for the column safety. 3,4 It may be damaged in case of even the use of only a little amount of inappropriate solvents used as mobile phases and/or sample solvents. These limitations represent a disadvantage for new applications using these CSPs and, especially, preparative separation due to solubili-zation of analytes. To overcome these problems, therefore, the development of polysaccharide-derived covalently bonded CSPs has been of great interest and various results of different attempts have been reported