NEW ORGANIC MONOSIZED MICROSPHERES FOR USE IN ENANTIOMER SEPARATIONS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Monosized nonporous resin particles were prepared in aqueous medium by polymerisation of urea with formaldehyde in the presence of soluble F e(III) hydrolysis polymers. Measurements of the geometrical parameters showed that the material particle size distribution was in the range 2.5-3.5 mu m (average particle diameter 2.99 mu m with standard deviat ion 0.49), and had a sphericity index of 0.851. Particle pore-size was determined by gel permeation chromatography. The microspheres exhibit ed exceptional mechanical strength, chemical stability in the pH range between 1-13, and low tendency toward swelling in the solvents common ly used in liquid chromatography. The synthesis of a chiral urea-forma ldehyde based resin for the enantiomer separation of underivatized phe nylalanine by ligand exchange chromatography is reported.