Analysis of organic matter in soil, extracts and whole soils by pyrolysis mass spectrometry

This chapter describes and evaluates applications of mainly pyrolysis-field ionization mass spectrometry (Py-FIMS) to the analysis of soil organic matter (SOM) and of pyrolysis-gas chromatography /electron ionization mass spectrometry (Py-GC/MS) to structural studies on humic substances. The chapter presents fundamentals of pyrolysis-mass spectrometric methods. Mass spectrometry is one of the most expensive and sophisticated analytical techniques with respect to both the instrumental requirements and the skill and proficiency of the operating staff. In most agricultural soils, inorganic and organic soil constituents are so closely associated that it is necessary to separate the two before either can be examined in greater detail. This separation is usually achieved by extracting the SOM. The soil science literature contains a vast amount of information on the extraction of organic matter (OM) from soils by variety of reagents under widely differing experimental conditions. With recent developments in Py-FIMS, and its application to SOM and whole soils, it has become possible to investigate the effects of soil minerals on the thermal evolution of fulvic acids (FA) by this method. There are many other applications for solving problems of immediate concern and for better understanding of the quality and role of SOM in soils. © 1995, Academic Press Inc.