A comparison of various pyrolysis experiments for the analysis of reference humic substances

The interpretation of the results of pyrolysis studies of humic substances is fraught with difficulties if only a single analytical technique is emplo yed for substructure analyses. In this paper we have carried out investigat ions into humic substances utilising the additional information from the co mbination of gas chromatography/infrared spectroscopy and gas chromatograph y/mass spectrometry detection following Curie-point pyrolysis at five diffe rent temperatures. The results were compared to those obtained from convent ional flash pyrolysis. The aim was to ensure the validation of the results of the compounds identified by at least one other spectroscopic technique. Some 30 substances have been positively identified by infrared spectroscopy , although their appearance is dependent on pyrolysis method and temperatur e. Most assignments were validated by mass spectrometry or the substance cl ass confirmed. (C) 2001 Elsevier Science B.V. All rights reserved.