Novel reverse-phase ion pair-high performance liquid chromatography separation of heparin, heparan sulfate and low molecular weight-heparins disaccharides and oligosaccharides

In this study, by using tetrabutylammonium bisulfate as ion-pairing reagent, we were able to separate all the main heparin/heparan sulfate disaccharides generated by the action of heparinases along with the main Hep tetrasaccharide possessing a 3-O-sulfate group on the sulfoglucosamine unit and resistant to enzymatic action. Moreover, this novel HPLC method was able to separate and quantify uncommon disaccharides/oligosaccharides present in low molecular weight-heparins produced by chemical treatment with nitrous acid, dalteparin, or benzylation followed by alkaline hydrolysis, enoxaparin. Additionally, this procedure yields a sensitivity ∼4-times higher compared to conventional strong-anion exchange-HPLC separation. This was obtained by a common UV detector at 232 nm avoiding the use of complex procedures capable of increasing sensitivity by post-column derivatization. Finally, it is worth mentioning that disaccharide/oligosaccharide composition by HPLC and UV detection is a common analytical approach in quality control laboratories to evaluate heparins and low molecular weight-heparins structure and quality during their extraction and production. This simple HPLC approach offers high resolution and sensitivity for the rapid differentiation of pharmaceutical native heparins and derivatives and for the compositional analysis of small amounts of samples derived from biological sources at a glycosaminoglycans level of a few hundred nanogram.