Silica based phases for HPLC enantiomer separation in which CHIRAL-1 seperation is based on ligand exchange and CHIRAL-2 or CHIRAL-3 on charge-transfer and further interactions as well as on steric effects.
CHIRAL-1 based on an L-proline copper complex covalently bonded to spherical silica particles. The formation of ternary mixed ligand complexes via Cu(II) ions with the analytes and differences in the stability of the diastereomeric complexes cause the chromatographic separation. The eluent in the column is a 0,5 mM copper sulfate solution.
The column has recommended applications on enantiomers with two polar functional groups with a suitable distance such as α-amino acids, α-hydroxycarboxylic acids and N-alkyl-α-amino acids.
CHIRAL-2 is a so-called "brush type" phase. The chiral selector N-(3,5-dinitrobenzoyl)-D-phenylglycine is covalently bonded to spherical silica.
CHIRAL-3 features the L-conformation of the chiral selector.
The interaction modes involve charge-transfers, dipole-dipole interactions, hydrogen bonds and steric effects. The eluent in the column is n-heptane/2-propanol/TFAA (100:0.05:0.05, v/v/v).
Separations of enantiomers and diastereomers, the control of the optical purity of plant protectives and pharmaceuticals as well as product controls in chiral organic syntheses are recommended applications of the both columns.
EC guard columns are used for analytical EC columns with the Column Protection System guard column holder (554-5851).