Ion-pairing reversed-phased chromatography/mass spectrometry of heparin

Heparin and heparin-derived components are widely applied anticoagulant drugs used for amongst other applications medical treatment of deep vein thrombosis and pulmonary embolism. Depolymerisation of native heparin results in complex mixtures of sulfated linear oligosaccharides that are usually not well characterised. In order to further characterise such mixtures, two on-line ion-pairing reverse-phased chromatography electrospray ionisation (ESI) mass spectrometry methods have been developed. One of the systems allows the determination of more than 200 components in a medium molecular weight heparin preparation, whereas the other system can be used to separate isomeric heparin oligosaccharides after previous separation according to size. This latter system allows semi-preparative isolation of isomeric heparin oligosaccharides. The experimental setup includes on-line cation exchange in order to prevent the ion-pairing reagent from entering the mass spectrometer.