Molecular studies of insoluble organic matter in river sediments from Alsace-Lorraine (France)

Insoluble organic matter (IOM) from river sediments of Alsace-Lorraine (France) was examined by semi-quantitative pyrolysis-gas chromatography–mass spectrometry (Py-GC–MS). IOM in rivers can play a role in the production of noxious metabolites and mobilization of pollutants by complexation. The relative abundance of aliphatic hydrocarbons, aromatic hydrocarbons and heteroatomic compounds was determined in IOM from natural and pollutant sources and small and large rivers. A ternary plot of these compound classes allowed the natural and pollutant end members to be distinguished. The IOM of the small rivers was similar to the pollutant end member whilst that of the large rivers was similar to the natural sources. This semi-quantitative Py-GC–MS approach constitutes a promising tool for IOM characterization.