Coupling of microextraction by packed sorbents with gas chromatography with ionic liquid stationary phases for the determination of haloanisoles in wines.

A new method based on the coupling of microextraction by packed sorbents (MEPS) and gas chromatography with ionic liquid stationary phases for the determination of four haloanisoles in wine matrices is proposed. The analytes were concentrated in a C18 barrel insert and needle (BIN), desorbed with a small volume of an organic solvent, and determined by gas chromatography with electron-capture detection (GC-μECD). The influence of several factors on the efficiency of extraction, washing and elution steps was investigated. Additionally, ionic liquid stationary phases of very different polarities were evaluated in terms of efficiency. Under optimized conditions, the analytes were first extracted in the sorbent material and, after an adequate washing step, eluted with 50 μL of ethanol. An aliquot of 5 μL of this extract was further injected, using a programmed temperature vaporizer (PTV), into the chromatographic system. The yield of the overall procedure ranged from 48 to 60%; the reproducibility of the method, calculated as the relative standard deviation (RSD), was below 10% for all compounds, and the limits of detection ranged from 1.2 to 4.8 ng L(-1). External calibration was used in the determination of the target compounds in wine samples.