Headspace sampling is a means of introducing volatile compounds associated with a sample material without the use of solvent extraction. In static headspace, the sample is sealed into a vessel, warmed, and then a sample of the atmosphere surrounding the sample is withdrawn and injected into the injection port of the GC.

Dynamic headspace sampling is a technique which uses a flow of carrier gas through the sample vessel to increase the headspace sample size, and thus the sensitivity of the technique. Instead of allowing the sample to come to equilibrium in a sealed container, the sample is warmed and the headspace atmosphere is constantly purged out of the sample vessel and through a trap.

Here the analytes are collected, as in a purge and trap analysis, while the carrier gas is vented. After the collection step, the trap is heated and backflushed to transfer the adsorbed compounds to the GC for analysis. Since no solvents were used to prepare the sample for the GC, there is no solvent peak, no dilution of the compounds of interest, and no waste solvent to discard.