Determination of marine monosaccharides by high-pH anion-exchange chromatography with pulsed amperometric detection

In this study, a method was developed for the determination of ten monosaccharides in marine particulate matter utilizing high-pH anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). Samples were analyzed using a Dionex CarboPac PA1 column with a flow-rate of 1 ml/min and addition of 380 mM NaOH post-column. The effect of NaOH concentration (between 0.5 and 50 mM) on the monosaccharide separations expressed by the capacity factor (k') was tested. The results showed that one isocratic elution was unfit to discriminate properly arabinose, fructose, fucose, galactose, glucosamine, glucose, mannose, ribose, rhamnose and xylose. Thus, two isocratic elutions, at 2.5 and 15 mM NaOH, were necessary to separate and quantify with significant selectivity (alpha) and resolution terms (R(s)), respectively, glucose, mannose, xylose and fucose, rhamnose, arabinose, glucosamine, galactose, fructose and ribose. The method is linear for all sugars over the concentration range tested (25-250 ng per injection or 1-10 mg/g) expected in marine concentrated samples, and reproducibility was found to be satisfactory (1.7-4.8%), except for ribose (27%). Monosaccharide determinations from two kinds of marine matrix (hydrolyzates of surface sediment and of suspended particulate matter) are presented.