An efficient absorption spectroscopy system (100) is provided for detecting the presence of trace concentrations of gaseous species. In particular, a method of obtaining data regarding a gas analyte, comprising: providing the analyte from a gas chromatography column (130); providing the analyte to a gas flow cell (104); passing VUV wavelengths or less of light from a VUV source (110) through the gas flow cell (104); detecting absorption of the VUV wavelengths or less of light by the analyte through the use of a spectrometer (106, 154, 156) optically coupled to an optical output (142) of the gas flow cell (104); obtaining a three dimensional data set indicative of an amount of absorption of the analyte as a function of wavelength and time; and analyzing the three dimensional data set to determine an identity and quantity of the analyte.
