Flavor systems, ingeneral, are complexmixtures of organic compounds. Since
many of the components are volatile, they often canbeanalyzedusinggas
chromatography (GC). Flavor systems areevaluatedbyGC for anumber of
reasons. Flavor extractsmight be tested for quality control purposes, or to
determine if anewmaterial matches adesired flavor profile; or, flavor systems can
be “reverseengineered” toestimate the volatile composition.Withawide rangeof
compound types, boilingpoints and concentrations, theanalysis times canbequite
long. Additionally, complete resolutionof all componentsmight require twodifferent
stationary phases. For routineanalyses, an ideal separationwould involvea single,
rapid runwith complete resolutionof all target components. Two approaches for
achievinghigh speedGC separationswill bediscussed.
Oneapproach to reducedanalysis times utilizes fast oven temperatureprograms,
particularly useful if awide rangeof boilingpoints are represented. Toensure fast,
reproducible temperaturegradients anauxiliary heatingunit canbe introduced into
theGCoven. For complex systems that requireadual columnanalysis for complete
characterization, two-dimensional GC techniques can significantly reduceanalysis
times. Flow-modified selectivity tuningusing twodissimilar stationary phases in
serieswill bediscussed. In this technique, the columns are joinedat a junctionpoint
connected toa sourceof carrier gas. The flow through the first column canbe
stopped for short periods of time, enhancing the separationof target compounds.
Introduction
