Comparison of dynamic headspace concentration on Tenax with solid phase microextraction for the analysis of aroma volatiles

Two different headspace extraction methods for aroma volatiles were compared: headspace solid phase microextraction (SPME), using both poly( dimethylsiloxane) (PDMS) and polyacrylate (PAc) fibers, and dynamic headspace trapping using a glass-lined stainless steel trap, containing Tenax TA. The samples studied were a cola and a diet cola. Extraction time and temperature were the same for each analysis. The dynamic headspace method extracted more volatiles from both samples than did SPME with either filament. The profile obtained using the PDMS fiber was similar to that of the Tenax TA extract but was much less intense. The PAc extract contained fewer components than the PDMS extract but included two polar volatiles not present in the other two extracts. Reproducibilities were similar for both techniques. Qualitative differences between the two cola samples were small, although the total quantity of volatiles extracted from the cola was up to 4 times greater than for the diet cola.