MINERAL EFFECTS ON THE PYROLYSIS-FIELD IONIZATION MASS-SPECTROMETRY OF FULVIC-ACID

Fulvic acid (FA), physical mixtures of FA with quartz, Na-montmorillonite, and kaolinite, and FA-Na-montmorillonite and FA-kaolinite complexes were analyzed by pyrolysis-field ionization mass spectrometry (Py-FIMS). Use of this method made it possible to detect the following six major groups of FA components: carbohydrates, phenols, lignins, lipids, alkylaromatics, and N compounds, and to determine how the thermal evolution of these components was affected by the presence of minerals during pyrolysis. The thermal evolution of the six major FA components was delayed by the FA-mineral mixtures but substantial retention of specific groups of FA components was shown only in the FA-clay complexes. Thus, FA components retained by the clays in FA-clay complexes were more thermostable than those in physical mixtures with FA. Pyrolysis-field ionization mass spectrometry was found to have considerable potential for enhancing our understanding of the effects of the presence of minerals on the thermal behavior of FA.