New approaches on gas phase molecular absorption spectrometry detection in gas chromatography

A hyphenated technique for coupling a spectrophotometric detector to a gas chromatograph with a packed column is described. The packed column was connected directly to the flow cell (path length 1 cm) which was placed in a UV-visible molecular absorption spectrophotometer with diode array detector. This detection system was employed for separating and determining benzene, toluene, 1,4-xylene, 1,2-xylene and mesitylene. Molecular absorption spectra of all the separated compounds have also been obtained. A new possibility for coupling capillary gas chromatography and gas phase molecular absorption spectrometry is currently being tested. In this new case, two fibre optics are used and the measurement is performed in the capillary column.