Dispersive liquid–liquid microextraction using non-chlorinated, lighter than water solvents for gas chromatography–mass spectrometry determination of fungicides in wine

A novel and low solvent consumption method for the sensitive determination of fungicide residues in wine samples is proposed. Analytes were extracted by dispersive liquid–liquid microextraction (DLLME) and further determined by gas chromatography–mass spectrometry (GC–MS). Under optimized conditions, a binary mixture of acetone and 1-undecanol (0.5 and 0.05 mL, respectively) was used to extract target compounds from diluted (1:1) wine samples. After centrifugation, the floating phase of 1-undecanol was solidified and separated from the liquid hydro-alcoholic matrix. Thereafter, it was allowed to melt at room temperature and injected in the GC–MS system. The method showed relative standard deviations (RSDs, %) below 13%, limits of quantification (LOQs) between 0.2 and 3.2 ng mL−1 and linear responses for concentrations up to 300 ng mL−1. The efficiency of the liquid-phase microextraction process was scarcely affected by the characteristics of wine samples, consequently pseudo-external standard calibration (using matrix matched standards of red and white wine) sufficed to achieve acceptable accuracy values: relative recoveries from 81 to 120%. The applicability of the method was demonstrated with commercial wine samples.