title: Solvent-enhanced headspace sorptive extraction in the analysis of the volatile fraction of matrices of vegetable origin.
abstract: The solvent-enhanced headspace sorptive extraction technique aims at modifying PDMS polarity using a solvent to increase its concentration capability. In solvent-enhanced headspace sorptive extraction, a PDMS tubing closed at both ends by small glass stoppers and filled with an organic solvent is suspended in the sample headspace for a fixed time. After sampling, the sampled analytes are recovered from the PDMS tubing by thermal desorption and online transferred to a GC-flame ionization detector or GC-MS system for analysis. Cyclohexane, iso-octane, ethyl acetate, acetone, acetonitrile and methanol were tested as PDMS modifiers to sample the volatile fractions of sage (Salvia lavandulifolia Vahl.), thyme (Thymus vulgaris L.) and roasted coffee. Ethyl acetate was found to be the most effective PDMS modifier for all matrices investigated; although to a lesser extent, cyclohexane also increased component recoveries with sage and thyme. Acetone, acetonitrile and methanol did not increase PDMS recovery, while isooctane was excluded because of its interaction with the polymer. The results show that solvent-modified PDMS extends the range of sampled headspace components with different polarities, increases the recovery of many of them, improves sensitivity in trace analysis, speeds up recovery and gives repeatability comparable with that of unmodified PDMS.
authors.affiliation: Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Torino, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sgorbini
authors.forename: Dilma
authors.initials: D
authors.lastname: Budziak
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: Pat
authors.initials: P
authors.lastname: Sandra
authors.forename: Carlo
authors.initials: C
authors.lastname: Bicchi
mesh_terms: D005410:Flame Ionization / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009822:Oils, Volatile / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D014675:Vegetables / Q000737:chemistry*
chemical_list: D009822:Oils, Volatile; D010936:Plant Extracts; D012997:Solvents