Experimental design of magnetic ionic liquid ultrasound-assisted dispersive liquid-liquid microextraction for the determination of 5-HMF in honey samples

A green, sensitive, and accurate ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) pro-cedure using a magnetic ionic liquid (magnetic-IL) was optimized for the preconcentration and extraction of 5-hydroxymethylfurfural (5-HMF) in honey samples collected from different regions of Turkey prior to analysis by UV-VIS spectrophotometer. A multivariate optimization strategy was employed to optimize microextraction factors (pH, [C8mim]FeCl4 magnetic-IL amount, ultrasound time, dispersing agent volume) affecting the magnetic-IL UA-DLLME. Since the separation of the phases was achieved with a neodymium magnet, centrifu-gation step was not necessary. Under optimal experimental conditions, linear range of 3-600 mu g L-1, limit detection of 1.0 mu g L-1 and an enrichment factor of 175 were obtained. The magnetic-IL UA-DLLME procedure was successfully applied for the analysis of 5-HMF in the honey samples, and the extraction recovery were in the range of 92-103%. To evaluate the precision of the magnetic-IL UA-DLLME procedure, relative standard de-viations from the inter-day assay and intra-day assay ranged from 3.9% to 5.1% and 3.3-4.2%, respectively. This study reports the first application of magnetic-IL with the UA-DLLME technique based on multivariate optimi-zation for the determination of 5-HMF in different honey samples.