Microwave assisted extraction combined with dispersive liquid-liquid microextraction as a sensitive sample preparation method for the determination of haloanisoles and halophenols in cork stoppers and oak barrel sawdust

In this paper, a method based on microwave assisted extraction (MAE) in combination with dispersive liquid-liquid microextraction (DLLME) has been proposed as a new approach for the sensitive determination of cork taint responsible compounds in cork stoppers and oak barrel sawdust. For this purpose, haloanisoles and halophenols were extracted from the solid samples using a MAE method. Subsequently, a DLLME-derivatisation procedure was applied on the MAE extracts and the analytes were determined by gas chromatography-electron capture detection (GC-ECD). Parameters affecting the DLLME-derivatisation method were exhaustively investigated by means of experimental design methodology. Once optimised, the proposed method showed satisfactory linearity (correlation coefficients over 0.991), repeatability (below 10.4%) and inter-day precision (below 11.2%). Detection limits obtained were similar or even lower than previously reported. The results obtained proved the suitability of the combination of MAE with DLLME as a sensitive sample preparation methodology for the analysis of haloanisoles and halophenols in solid enological matrices. (C) 2012 Elsevier Ltd. All rights reserved.