One of the objectives of the Tritium Laboratory Karlsruhe (TLK) is to develop new analytical techniques or improve existing ones for the qualitative and quantitative determination of the composition of gas mixtures containing tritium. Among the analytical techniques (mass spectrometry, gas chromatography, laser Raman spectroscopy, calorimetry, ionisation chambers, etc.) available at die TLK, gas chromatography plays a special role because different gas chromatographs are used not only for basic and applied research, but also for infrastructure applications. The TLK gas chromatographs are evaluated on the basis of flow diagrams and typical chromatograms. Further details such as type of columns, detectors and detection limits are also given.