Analysis of hydrocarbons in coal and rock samples by on-line combination of thermodesorption, gas chromatography and mass spectrometry

GC-MS analysis of hydrocarbons, thermally mobilized from rock and coal samples (“thermodesorption”) at 320°C, provides valuable and readily available information of organic geochemical significance. Two oil shale and three coal samples of different rank have been selected for this study. The molecular patterns of compound classes of various saturated and aromatic hydrocarbons are recorded here by employing mass chromatography of selected ions. The method described is of particular importance for the detection of those volatile constituents in coals and sedimentary rocks, which are usually not recovered during elaborate workup procedures (i.e. solvent extraction, liquid chromatography) due to evaporation losses.