With the Dräger silica gel tubes, the hazardous substances contained in the air are first collected via active sampling, e.g. Dräger tube pump X-act 5000. The sample is then qualitatively and quantitatively tested in the laboratory using instrumental analysis such as gas chromatography (GC), high-performance liquid chromatography (HPLC), UV-VIS photometry or IR spectroscopy. Measurements: 10