Determination of Oligosaccharide Patterns in Honey by Solid-Phase Extraction and High-Performance Liquid Chromatography

Summary

A simple analytical technique for the determination of the di-, tri, and oligosaccharide profiles in honey has been developed. The method consists in the previous separation of these analytes from the more abundant monosaccharides D-(+)-glucose and D-(−)-fructose through a solid phase extraction procedure. Porous graphitic carbon cartridges have been used; the washing solution was distilled water at 4 °C, and the elution of the oligosaccharides was achieved with a (1:1) water/acetonitrile mixture at 50 °C. An aliquot of the eluate was reacted with 4-(3-methyl-5-oxo-2-pyrazolin-1-yl)benzoic acid (PMPA) and the derivatives were analysed by HPLC with UV-detection. Chromatographic conditions were thoroughly chosen to separate most of the derivatives. The quantitative performance was evaluated by replicate measurements at seven analyte levels. The calibration curves obtained for four sugars showed excellent linearity over a range of 10–3000 pmol. Limits of detection and quantification were 20 and 150 picomoles, respectively. The methodology has been successfully applied to the characterization of five honey samples, which were produced in different geographical regions of Province of Buenos Aires.