In these techniques, analytes are adsorbed on a thin strip made of polymer,
which contains activated charcoal [3]. It is hung inside a container with
the sample in such a way as to stay in contact with the head-space vapour,
but not touch the sample. After an adequate period the strip is pulled out
and analytes are extracted by an appropriate solvent. If GC/FID is used, carbon
disulfide is the most favourable solvent. If GC/MS is used it is better to
apply a less toxic but equally effective solvent, such as diethyl ether [25].