Optimisation of a sensitive method based on ultrasound-assisted emulsification–microextraction for the simultaneous determination of haloanisoles and volatile phenols in wine

Abstract

In this study, an ultrasound-assisted emulsification-microextraction (USAEME) has been optimised for the sensitive determination of haloanisoles (2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA)) and volatile phenols (4-ethylphenol (4-EP), 4-ethylguaiacol (4-EG), 4-vinylphenol (4-VP) and 4-vinylguaiacol (4-VG)) in wine using gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). Optimisation of USAEME method was performed by evaluating the different parameters that influence the recovery of the analytes in the extract. Firstly, extraction solvent was selected. Subsequently its volume, the ionic strength and the time and temperature at which the extraction must be performed were simultaneously evaluated by means of experimental design methodology. After optimisation step, the analytical characteristics of the method were evaluated. Satisfactory linearity (with correlation coefficients over 0.989), repeatability (below 11.5%) and inter-day precision (below 11.7%) were obtained for all target analytes. For all the studied compounds, detection limits obtained were similar or even lower than previously reported. In addition, the developed method was successfully applied to the analysis of wine samples. To the best of our knowledge, this is the first time that USAEME has been applied to simultaneously determine the compounds responsible for cork taint and Brett character in wine.