Solid Phase Microextraction (SPME) and Stir Bar Sorptive Extraction (SBSE) are well known and established sample preparation techniques for GCMS analysis of flavors and fragrances in beverages, such as wine and whiskey.  Their ease of use and wide range of extraction capability make them a common ‘first step’ in finding the source of flavor notes in many beverages, including those described as “smoky”, “char”, etc. They are not without limitations.  SPME has limited extraction capacity and its selectivity (determined by the composition of the fiber) is both a strength and a weakness.  SBSE’s use of a thick (relative to SPME) film of polydimethylsiloxane (PDMS) overcomes most of the capacity issues of SPME, but the non-polar nature of PDMS means that extraction of polar flavor compounds is sometimes limited.  For smoky-type flavor notes this is particularly problematic, as the sources are very often polar molecules, such as phenols and pyrazines.<br/>A novel technology has been developed to address some of these short comings.  Thin-Film SPME (TF-SPME) uses many of the same substrates as SPME but they are placed on a carbon fiber mesh.  The mesh allows for a much higher mass of substrate to be used relative to traditional SPME.  These robust TF-SPME meshes can be inserted into vials and left <i>in situ</i> for long sampling periods (much like SBSE stir bars).  The longer extraction times and substrate masses provide more extraction capacity, but the carbon fiber meshes permit the use of substrates much more amenable to polar flavor compounds than PDMS. The use of TF-SPME, both alone and in addition to SBSE will be demonstrated.  Their use for polar compounds such as phenols with be discussed, with a focus on analytical performance.  The coupling of TF-SPME sample preparation to GC-olfactometry will also be shown.   <br/>

Thin-Film SPME:  A novel approach to the analysis of polar flavor molecules in beverages

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.