Abstract: An apparatus for taking samples by thermal desorption of compounds that are adsorbed on solid adsorbents contained in a sample tube. An injector has a recess for accommodating the sample tube and a connection for a capillary column of a gas chromatograph. The compounds are desorbed into such capillary column by means of a stream of carrier gas passing through the sample tube. An injector extension is fastened to the injector and has a recess for accommodating the sample tube. The recess of the injector extension is flush with the recess of the injector. A push rod is guidable in the injector extension for pushing the sample tube from a position in the injector extension into a position within the injector. A carrier gas inlet communicates with the recess in the injector extension for admitting a carrier gas therein. A plug is disposed at an end of the push rod for gripping the sample tube. The plug includes a bore for effecting communication between the carrier gas inlet and the interior of the sample tube.