In this technique, an adsorbent is coated onto a fused silica fibre, which
can be pushed in or out of a needle on a special sampler [1]. Samples are collected
by inserting the needle into the head-space phase and exposing the fibre
with adsorbent. As optimisation research shows, a few minutes’ exposure
is enough for an equilibrium to be established [33]. Next the needle is
inserted into the chromatograph injector, where the adsorbed compounds
are thermally desorbed in the heightened temperature of the injector and
are transported by carrier gas into the chromatographic column.