Dispersive Liquid-Liquid Microextraction Method for HPLC Determination of Phenolic Compounds in Wine

Abstract

A fast and efficient dispersive liquid-liquid microextraction (DLLME) method was developed for extraction of phenolic compounds from red, rose, or white wine followed by HPLC determination in this study. After different extraction solvents and conditions were evaluated, the fastest and highest efficiency extraction of 12 phenolic compounds including gallic acid, protocatechuic acid, chlorogenic acid, catechin, vanillic acid, caffeic acid, syringic acid, epicatechin, p-coumaric acid, trans-ferulic acid, quercetin, and kaempferol was achieved by using 1000 μL of ethyl acetate as an extraction solvent and 500 μL of acetonitrile as a dispersive solvent. The mixtures of solvents were mixed with 1000 μL of wine sample for 10 s of extraction time. The extractions were carried out two times. Under the optimal condition, the extraction recoveries of 12 phenolic compounds were in a range from 76.56 to 137.74%. Meanwhile, the linearity, sensitivity, and precision of an optimized HPLC analysis method were evaluated. The results showed that each phenolic compound had a good regression coefficient (R 2). The limits of detections and quantifications for all the 12 compounds were at 0.001 to 0.133 and 0.004 to 0.433 mg/L, respectively. The relative standard deviations of intra- and inter-day determinations of the 12 compounds were below 6.58 and 4.11%, respectively. The results showed that the red wines had the highest concentration of total phenolic compounds (48.74–196.07 mg/L), followed by the rose wine (31.11 mg/L) and white wine (11.18–30.39 mg/L). Catechin was the dominant phenolic in all the wines (exception of wine sample W8) and ranged from 3.02 to 72.89 mg/L. In general, the developed dispersive liquid-liquid microextraction with HPLC analysis is a fast and efficient method to determine the phenolic compounds in wine.