Comparison of gas phase extraction techniques

Analysis of coffee powder using DHS, HS-SPME and Static Headspace

In order to compare different gas phase extraction techniques, 100 mg samples of a ground coffee were analyzed using static headspace, headspace-SPME and DHS. Comparable extraction conditions were chosen:

 Temperature 40 °C 40 °C 40 °C
 Extraktion time 30 min 30 min 10 min 
 Purge flow     20 ml/min 
 Adsorbent DVB/Carboxen/PDMS Tenax

It can be seen from the sample chromatograms and the bar graph showing relative peak areas (DHS response normalized to 100%), that DHS provided the highest response for the analytes that were determined.

For most analytes, DHS provided relative standard deviations well below 5%, which is equal to or better than the other techniques.