Astec CLC Copper Ligand Exchange Columns

Features

• Separates α-hydroxy carboxylic acids, amino acids and other α-bifunctional compounds
• High selectivity with simple mobile phases
• Copper complex read @ 254nm UV
• CSP structures contain all known mechanisms for chiral selectivity
• Simple reversal of elution order, CLC-L vs. CLC-D
• Excellent reproducibility

The Astec CLC phases are based on coupling an enantiomeric form of an amine to a proprietary Astec derivative to create an appropriate distance for copper coupling. Using the copper ligand concept, this phase resolves hydroxy acids like lactic, malic, tartaric and mandelic. This phase can also resolve amino acids and other amines by the same mechanism. It has been reported that, in addition to amino acids, other bifunctional racemates like amino alcohols can be resolved. In theory, any analyte that can complete the coordination with the copper ion can be resolved. For the CLC-D column,the L enantiomer generally elutes before D with the exception of tartaric acid where the D elutes first. The CLC-L column has the opposite elution order and the D enantiomer elutes before L.

Generally, we recommend the CHIROBIOTIC T for all amino acid separations that are detected at 200-210nm UV. Two amino acids in particular have worked better on the Astec CLC column for low levels of detection since the copper complex is detected at 254nm UV. They are proline and aspartic acid. Both of these amino acids can be resolved on the CLC-D or CLC-L in 5mM CuSO₄ with the usual reversal of elution order from the CLC-D to CLC-L. Other analytes separated include free α-amino acids, malic acid and 3-phenyl lactate.