title: Dual-phase twisters: a new approach to headspace sorptive extraction and stir bar sorptive extraction.
abstract: The fields of applicability of headspace sorptive extraction (HSSE) and stir bar sorptive extraction (SBSE) using polydimethylsiloxane (PDMS) as sorbent have been intensively discussed and widely described. One of the limits of sorptive extraction is that PDMS (i.e. an apolar phase) is the only polymer currently in use making it difficult to recover polar analytes from complex or multi-ingredient matrices and those with very volatile components (C1-C4 analytes). Dual-phase twisters are here introduced as new tools for HSSE and SBSE to overcome the above limits. Dual-phase twisters combine the concentration capabilities of two or more sampling materials operating in different ways (in this case sorption and adsorption). The new twisters consist of a short PDMS tube the ends of which are closed with two magnetic stoppers, thus creating an inner cavity that can be packed with different types of adsorbents like activated carbons. The concentration capability of dual-phase twisters was evaluated by using them for the HSSE and SBSE sampling of a number of matrices in the vegetable, food and environmental fields. The contributions made by different carbons to recovery, repeatability and intermediate precision were also investigated.
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, via Pietro Giuria 9, I-10125 Torino, Italy. carlo.bicchi@unito.it
authors.forename: Carlo
authors.initials: C
authors.lastname: Bicchi
authors.forename: Chiara
authors.initials: C
authors.lastname: Cordero
authors.forename: Erica
authors.initials: E
authors.lastname: Liberto
authors.forename: Patrizia
authors.initials: P
authors.lastname: Rubiolo
authors.forename: Barbara
authors.initials: B
authors.lastname: Sgorbini
authors.forename: Frank
authors.initials: F
authors.lastname: David
authors.forename: Pat
authors.initials: P
authors.lastname: Sandra
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D012828:Silicones / Q000737:chemistry
chemical_list: D004129:Dimethylpolysiloxanes; D012828:Silicones; C013830:baysilon