High performance liquid chromatographic determination of 2-furaldehyde and 5-hydroxymethyl-2-furaldehyde in honey

A method of determination of 2-furaldehyde (F) and 5-hydroxymethyl-2-furaldehyde (HMF) in honey 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 reversed-phase 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, since the derivatives of F and HMF are well separated from the other components of the mixture under examination. Recoveries of 95-99% were obtained from honey spiked at different levels with both analytes. The detection limit is of the order of 10 μg/kg of honey and reproducibility (mean of six determinations) is ±3% for F and ±2% for HMF.