Using Three Types of Twister Phases for Stir Bar Sorptive Extraction of Whisky, Wine and Fruit Juice

This paper describes a novel ethylene glycol- (EG) and silicone based combined sorbent phase developed for stir bar sorptive extraction (SBSE) using the GERSTEL Twister™. EG-Silicone, polyacrylate (PA), and polydimethylsiloxane (PDMS) Twisters were used separately to perform SBSE on whisky, white wine and multivitamin juice in order to determine the usefulness of these phases for generating qualitative flavor profiles of beverages. The Twisters were subsequently thermally desorbed and the analytes determined using gas chromatography-mass spectrometry (GC/MS) based on both polar and non-polar GC columns. The pH stability of the EG-Silicone Twister was studied in wine samples and in aqueous standards. The EG-Silicone Twister extracted a broader range of substances from whisky, wine and multivitamin juice compared with PA Twister and PDMS. Most phenols and polar aromatic compounds could be extracted with EG-Silicone and PA Twisters. It was found that SBSE based on EG-Silicone phase results in the extraction of significantly larger amounts of the polar compounds than the PDMS- or PA based Twisters. The EGSilicone Twister also showed good extraction efficiency for other polar compounds such as more volatile esters and fusel alcohols. Due to its PDMS basis, non-polar compounds such as long carbon-chain ethyl esters, lactones, and terpenes are extracted with good recovery as well.