HPLC Determination of Formaldehyde in Fermented Wine and Beverage with Microwave Assisted Derivatization and Ionic Liquid-Based DLLME

A method based on HPLC coupled with microwave-assisted derivatization and ionic liquid-based dispersive liquid-liquid microextraction (DLLME) was developed for determination of formaldehyde in fermented wine and beverage. 2,4-dinitrophenylhydrazine (DNPH) was used as the derivatization reagent, 1-octyl-3-methylimidazolium hexafluorophosphate as extraction solvent, and acetonitrile as disperser. The sample solution was then irradiated at 300 W of microwave power for 60 s and centrifuged. Formaldehyde derivatives were extracted into the ionic liquid, and then dispersed in acetonitrile for HPLC analysis. The SB-C18 column was used as stationary phase and a mixture of water and methanol as mobile phase. UV-detection was measured at 355 nm. The linear relationship between the peak area and the mass concentration of formaldehyde was in the range of 1.00-100 μg·L-1, with detection limit (3S/N) of 0.16 μg·L-1 and limit of quantification (10S/N) of 0.53 μg·L-1. Tests for recovery were made by adding standard samples to draft beer, wine, cola and orange juice samples, giving recovery rates in the range of 92.5%-99.1% and RSD (n=5) in the range of 2.6%-7.8%.