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.

Headspace Sampling: An “Evergreen” Method in Constant Evolution to Characterize Food Flavors through their Volatile Fraction

“…Two main approaches have been proposed: (1) replacing PDMS with a more polar polymer having comparable characteristics and performance 78,79 or (2) modifying the polarity of PDMS: in the authors' laboratory, this aim has been achieved in two ways, i.e., with dual-phase Twisters (DP-Twisters) 80 or by using SE-HSSE. 81…”

Validation of a headspace trap gas chromatography and mass spectrometry method for the quantitative analysis of volatile compounds from degraded rapeseed oil

“…For this reason, it is essential to be able to quantify these products in the headspace of degraded edible oils. Different methods have already been developed and validated for the analysis of volatile molecules present in the headspace (HS) of edible oils [8]. More specifically, hexanal, a degradation product from linoleic acid oxidation [9], was a major compound considered in many studies.…”

Vortex‐ and CO2‐gas‐assisted liquid–liquid microextraction with salt addition for the high‐performance liquid chromatographic determination of furanic compounds in concentrated juices and dried fruits

“…HPLC with UV , diode array detection (DAD) or MS are at present the most commonly used techniques for the determination of furanic compounds. GC coupled with flame ionization detection (FID) or MS has also been used. Although some furanic compounds are volatile, derivatization step is still required to overcome the strong interaction with the GC column.…”

“…Alternatively, microextraction techniques have been proposed. SPME either with direct immersion (DI) or headspace (HS) sampling have been used for the analysis of furanic compounds in different matrices (e.g., honey , vinegar , coffee , apple , beer , etc.). Stir bar sorptive extraction (SBSE) and HS‐LPME have also been used for the extraction of furfurals in foodstuffs .…”