Filter-vial dispersive solid-phase extraction as a simplified clean-up for determination of ethylphenols in red wines

Abstract

In-vial filtration with dispersive solid-phase extraction (d-SPE) clean-up of QuEChERS (quick, easy, cheap, effective, rugged and safe) extracts is proposed for the determination of ethylphenols (EPs) in red wines. Analytes were extracted from 5 mL wine sample (previously alkalinized with 0.5% sodium hydroxide) using 5 mL acetonitrile. For phase separation, 1.5 g NaCl and 4 g anhydrous MgSO4 were added. Then, a 0.5 mL aliquot of the partitioned supernatant was cleaned-up using d-SPE and in-vial filtration with a combination of anhydrous CaCl2 (100 mg) and primary-secondary amine (PSA, 25 mg) as sorbents. The proposed method provided limits of quantification (LOQs) ranging from 0.024 to 0.04 mg L−1. Considering matrix-matched calibration as quantification technique, the recoveries (accuracy) ranged between 73% and 116%. The method was applied for the determination of EPs in 15 commercial wines of Argentina, where 4-EP was quantified at concentrations ranging from 0.25 to 3.01 mg L−1.