Salting-out-assisted liquid–liquid extraction of 5-hydroxymethylfurfural from honey and the determination of 5-hydroxymethylfurfural by high-performance liquid chromatography

Abstract

5-Hydroxymethylfurfural (HMF) is an important index for evaluating the quality of honey. In the present study, the recovery of HMF via the salting-out-assisted liquid–liquid extraction (SALLE) was systematically investigated to develop a simple, rapid, and effective method for the determination of HMF in honey. Results indicated that at the concentration of 70 : 30 (acetonitrile : H₂O, v/v), sodium carbonate showed the best recovery of HMF from honey with the 0.5 g addition amount of salt. Compared with two other homogenous liquid–liquid extraction methods, i.e. subzero temperature-assisted liquid–liquid extraction and hydrophobic solvent-assisted liquid–liquid extraction, SALLE showed an advantage of higher recovery for HMF. In addition, fructose and glucose were analyzed to investigate the residue of sugars in the extractive. Results demonstrated that the SALLE method could dramatically reduce the residual contents of these two sugars. In addition, SALLE showed the advantages of less consumption of samples and extraction solvents. Finally, the developed method was fully validated and applied for real honey samples. The analysis results obtained using the present method were comparable to those obtained using the official method; this indicated that the proposed method could be used as an alternative method for the routine quality control of HMF in honey.