CARBOHYDRATE CHROMATOGRAPHY - TOWARDS YOCTOMOLE SENSITIVITY

In attempting to analyse complex carbohydrates by HPLC or capillary el ectrophoresis (CE) the chromatographer is faced with many challenges, The diversity of oligosaccharide structures described to date and thei r poor resolution on many chromatographic systems present a significan t challenge to the chromatographer. In addition to this, the non-chrom ogenic nature of most carbohydrates greatly decreases the sensitivity of UV detection and refractive index is not an option for sensitive an alysis. Over the last five years there have been significant advances in separation and detection methods for carbohydrates, and in this pap er we will attempt to describe the most significant advances and highl ight potential future developments. The detection of 200-300 fmol (23 x 10(-13) mol) of oligosaccharides can now be readily achieved using e lectrochemical detection or fluorescence detection (after labelling) w ith conventional HPLC columns and detectors. Miniaturized separation s ystems have greatly increased sensitivities with a CE-laser induced fl uorescence instrument detecting as little as 100 yoctomoles (1 x 10(-2 4) mol).