[Analyse of sugars in beer and wort using high performance anion-exchange chromatography coupled with pulsed...

The method of the simultaneous and direct analysis of eleven sugars, including monosaccharides, disaccharides and oligosaccharides, was established using high performance anion-exchange chromatography (HPAEC) coupled with pulsed amperometric detection (PAD) using an Au working electrode and a pH-Ag/AgCl reference electrode. The separation was accomplished on a CarboPac PA-100 column by using gradient elution consisting of water, 0.25 mol/L NaOH and 1 mol/L NaAc as mobile phase at a flow rate of 0.25 mL/min. Under these conditions, glucose, fructose, sucrose, maltose, isomaltose, maltotriose, isomaltotriose, maltotetraose, maltopentaose, maltohexaose and maltoheptaose were separated in 40 min. Then sugars were detected directly with PAD method without any derivatization reaction, and there was no need to employ complicated pretreatment procedures to the samples before analysis. The detection limits (S/N = 3) for the sugars were 13-88 pg. The proposed method was applied for the determination of the 11 sugars in beer and wort samples satisfactorily, with the spiked recoveries of most sugars ranging from 81% to 107%. In addition, some potential transition mechanism of the sugars during the brewage procedure can be educed from the comparison of sugar contents between beer and wort.