Fig. 9.

a On-flow ¹H NMR-detected WAX chromatogram of heparin and OSCS. The slices taken through the chromatographic peaks show the ¹H NMR spectra of OSCS, heparin, and acetate, which was present as an unexpected impurity. The asterisk represents residual acetonitrile as a column contaminant. b Stop-flow ¹H NMR spectrum of heparin. The spectrum was acquired from a single 25 μL injection of a sample containing 40 mg/mL of heparin. Signals: a, H-1 of GlcNS; b, H-1 of Ido2S; c, H-1 of IdoA; d, HDO; e, H-6 of GlcNS6S; f, H-2 of IdoA2S; g, H-3 of IdoA2S; h, H-4 of IdoA2S; i, H-5 of GlcNS6S; j, H-4 of GlcNS6S; k, H-3 of GlcNS; l, H-2 of GlcA; m, H-2 of GlcNS6S; n, N-acetyl; asterisk, residual acetonitrile. Adapted from [138] with permission