Direct determination of 2,4,6-tricholoroanisole in wines by single-drop ionic liquid microextraction coupled with multicapillary column separation and ion mobility spectrometry detection

Abstract

This article evaluates the capability of single drop ionic liquid microextraction coupled with multicapillary column (MCC) and ion mobility spectrometry (IMS) for the determination of 2,4,6-trichloroanisole (2,4,6-TCA) in wines. The proposed methodology permits the direct analysis of the samples without any additional treatment other than dilution. This is achieved thanks to the selectivity provided by the ionic liquid selected as extractant, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide, as well as the response of the analyte in the IMS working in negative ionization mode. Moreover, the multicapillary column avoids the interference of ethanol in the ion mobility spectra. The analysis of the sample takes ca. 35 min to be completed. The limit of detection was low as 0.01 ng L −1 using 2 mL of wine sample. Different calibration curves were constructed using aqueous standards, red and white wines, being the signals comparable, with an RSD similar to the method variability. Finally, a set of samples of different nature and packed in different containers were analysed. It was found than those with cork stoppers presented the highest concentration of 2,4,6-TCA.