Improved method for the analysis of alpha-galactosides in pea seeds by capillary zone electrophoresis - Comparison with high-performance liquid chromatography triple-pulsed amperometric detection

A capillary zone electrophoretic (CZE) method is described for the analysis of the raffinose family of oligosaccharides (RFO) in pea seeds. Extraction of RFO was carried out in 80% ethanol and the extract was passed through a Sep-Pak C-18 cartridge. This proved to be an improvement on the currently accepted purification technique. High-quality electrophoregrams were obtained which allowed the separation and quantitation of sucrose, raffinose, stachyose and verbascose. The CZE results were compared with those obtained by anion-exchange high-performance liquid chromatography coupled to a triple-pulsed amperometric detection (HPAC-PAD). The samples were obtained from four pea strains which were near-isogenic except for genes at the r and rb loci. A high degree of precision and reproducibility was obtained for the RFO compositions of all the pea strains. No statistically significant differences (p less than or equal to 0.05) were found between the two analytical techniques using paired Student-t tests.