"Direct resolution of organic acid enantiomers on a novel polymer-based stationary phase"

A chiral packing for high-performance liquid chromatography was obtained by copolymerization of urea with formaldehyde in the presence of an optically active amino acid derivative. Spherical particles with a mean bead size of 6 μm were evaluated as stationary phases with respect to their chemical stability and chromatographic performance. Electrostatic interactions govern the overall kinetics of the retention in the chromatographic process, so that ion pairing seems to be responsible for the chiral recognition. Increasing the column temperature improves the chromatographic pattern considerably, and the resolution and peak shape are similar to those in the usual high-performance liquid chromatographic separations. The support is easy to pack and yields good column lifetimes. Its application to the resolution of some organic acid racemates is illustrated.