Novel HPLC – Fluorescence methodology for the determination of methylglyoxal and glyoxal. Application to the analysis of monovarietal wines “Ribera del Guadiana”

•3,4-Diaminopyridine is proposed for first time to derivatization of wine samples using fluorescence detector.•Glyoxal and methylglyoxal determined in wines by HPLC takes less than 4min without clean-up.•The method has been applied to wines from Denomination of Origin “Ribera del Guadiana” (Spain).•The values found are in agreement with the literature. The determination and quantification of α-dicarbonyl compounds, glyoxal and methylglyoxal, in “Ribera del Guadiana” monovarietal wines (Extremadura, Spain) without sample clean-up has been carried out by HPLC with spectrofluorimetric detection (307/371nm). For this purpose, a derivatization step with the new reagent 3,4-diaminopyridine at pH 2 during 120min at 90°C has been included. Afterwards, the sample could be injected in the chromatographic system with no clean-up, during a total run time of 4min. Several monovarietal wines (white, rosé and red) have been analyzed and the levels of these compounds for white wines were between 0.4–1.0mgL−1 glyoxal and 0.8–1.3mgL−1 methylglyoxal; and between 0.8–3.0mgL−1 and 0.5–1.8mgL−1 of glyoxal and methylglyoxal respectively, in red wines.