Chiralpak AS-H 5µm 50x4.6mm HPLC Column

The Chiralpak AS HPLC column 50x4.6mm, 5µm, based on amylose as the polysaccharide backbone. The specific modification used is amylose tris[(S)-α-methylbenzylcarbamate]; the chiral stationary phase is physically coated and immobilised on spherical silica. Chiralpak AS is primarily used in normal-phase chromatography and SFC, and separates enantiomers via hydrogen bonding, dipole–dipole interactions, π–π interactions and steric fit. Typical applications of the Chiralpak AS include chiral aromatic compounds, sterically hindered racemates, pharmaceutical intermediates and fine chemicals. As a coated phase, Chiralpak AS offers very broad, well-established selectivity and good loading capacity; the disadvantage lies in the limited choice of solvents, as highly solvent-aggressive media can damage the applied polysaccharide layer. Chiralpak AS utilises a chiral side chain and thus provides independent recognition compared with AD.

Performance Characteristics and Advantages

• Amylose- and cellulose-based polysaccharide phases with high enantioselectivity
• Immobilized Chiralpak phases with very broad solvent compatibility
• Coated Chiralpak phases with proven selectivity and good loading capacity
• Suitable for use in normal-phase HPLC, reverse-phase HPLC, polar-organic HPLC, and SFC
• Wide selection of complementary selectors for efficient chiral screening
• Specialized phases for amino acids, peptides, chiral acids, and ligand exchange methods

Additional Notes

Chiralpak includes both amylose-based and cellulose-based polysaccharide phases. In the immobilized phases, the chiral selector is fixed to the silica support. This allows for the use of significantly more organic solvents than with coated phases, which is particularly helpful when samples have limited solubility. Coated Chiralpak phases are based on polysaccharide derivatives physically applied to silica. They have a long history of use and often offer very high selectivity and good loading capacity. The most important limitation is solvent compatibility: mobile phases or sample solutions that can dissolve the polysaccharide layer must be avoided. Immobilized and coated variants with similar modifications are not necessarily chromatographically interchangeable. Immobilization increases robustness and solvent flexibility but can alter the spatial accessibility of the selector. Therefore, methods should be reviewed when switching between coated and immobilized phases and reoptimized as needed.

Legal Notices

Chiralpak is a registered trademark of Daicel Corporation, Osaka, Japan.