The natural heterogeneity of the oligosaccharide chains of glycoproteins requires that chromatography be an essential part of structural elucidation. Until recently, the rapid analysis of underivatised carbohydrates by HPLC was hampered, due to the extensive structural heterogeneity, by the absence of a chromatographic medium for satisfactory separation and by the lack of a sufficiently sensitive detection system. This problem has been overcome by the introduction of high pH anion exchange chromatography (HPAEC) with pulsed electrochemical detection (PED) which separates oligosaccharides as their oxyanions on micropellicular quaternary ammonium resins [1-10]. This technique resolves the linkage and branch isomers of neutral and anionic oligosaccharides to picomole sensitivity without pre- or post-column derivatisation. The DX-500 chromatography system is viewed as a major innovation in HPAEC-PED due to an improved sensitivity and resolution as a result of a new amperometric cell design and new digital detector signal processing. Our investigations have utilised the DX-500 in the analysis of various oligosaccharide mixtures in direct comparison with the DX-300 system that it has superceded.
- high ph anion exchange chromatography (HPAEC)
- alpha(1) acid glycoprotein
- immunoglobulin G
- pulsed-amperometric detection
- monosaccharide analysis