As in other techniques based on adsorption, the efficiency of concentration
of various compounds depends on the nature of the adsorbent. The majority
of papers published until now describe application of non-polar phases
of polydimethylosoloxane (PDMS) fibres. Fibres of this kind are effective in
concentrating crude oil derivatives with a high-boiling point, but show insufficient
affinity for polar, volatile compounds to be used for their analysis.
This problem was recently solved by introducing an active charcoal based
adsorbent under the trade name Carboxen®
. It is very effective in adsorption
of volatile compounds, including volatile polar analytes such as methanol,
ethanol and acetone [33].