High-Performance Liquid Chromatographic Determination of 2-Furaldehyde and 5-Hydroxymethyl-2-furaldehyde in Fruit Juices

A method for the determination of 2-furaldehyde (F) and 5-hydroxymethyl-2-furaldehyde (HMF) in fruit juices by high-performance liquid chromatography (HPLC) is described. The method is based on the formation of the 2,4-dinitrophenylhydrazones of carbonyl compounds and subsequent separation of these derivatives. Derivatization is carried out by utilizing an acidic solution of 2,4-dinitrophenylhydrazine in acetonitrile. Precipitation of the derivatives of carbonyl compounds is thus avoided, and direct injection of the sample into the HPLC system is allowed. The procedure offers a high specificity and a detection limit of the order of 10(-8) mol/L. Recoveries of 95-98% are obtained from apple juice spiked at different levels with both analytes. The reproducibility (mean of six determinations) is +/- 2% for F and +/- 3% for HMF.