Fractionation of low-molecular-mass heparin by centrifugal partition chromatography in the ion-exchange displacement mode

Centrifugal partition chromatography in the ion-exchange displacement mode allowed a preparative and efficient fractionation of low-molecular-mass hep arins from enoxaparin sodium. Amberlite LA2 - a lipophilic liquid secondary amine - was chosen as a weak anion exchanger. The biphasic system methyl i sobutyl ketone-water was selected. Protonated LA2 (10%, v/v) was added to t he organic stationary phase. Hydroxide (Na+, OH-) was chosen as a displacer in the aqueous mobile phase. The observed pH and concentration profiles ar e typical of displacement chromatography, as supported by numerical simulat ion. The Dubois test for the analysis of sugar content and an analysis of s ulfur content land consequently sulfatation rate) were carried out to monit or the effectiveness of the procedure. Moreover, the fractions were analyze d by high-performance size-exclusion chromatography and the H-1 NMR spectra confirmed the fractionation of the sample of enoxaparin sodium. (C) 2001 E lsevier Science B.V. All rights reserved.