How do I avoid water saturation when carrying out large-volume sampling of humid air?
To avoid water saturation of your analytical system, the simplest solution is to use only hydrophobic sorbents in your sampling tubes, such as Carbograph 2TD, which typically retains less than 1 mg on a standard tube and has a retention volume that is barely affected by the presence of water. Application Note 005 contains more information on the range of sorbents offered by Markes.
However, in some cases the use of strong, less hydrophobic, sorbents is unavoidable due to the nature of the compounds being studied. Application Note 026 gives more detail on the method parameters that can be used to manage high levels of water within samples and still get reliable results.