Analytical pyrolysis as a tool for the characterization of natural macromolecular organic matter. Reappraisal of its applications in agricultural and environmental sciences

Abstract

Well-known advantages of pyrolytical techniques (Py) have encouraged its application in the structural characterization of macromolecular organic matter, which is the subject of study in a wide number of fields including Agricultural and Environmental Sciences.Many studies has demonstrated the usefulness of both conventional flash pyrolysis in association with GC-MS and thermochemolysis in the presence of e.g., alkylammonium salts in releasing diagnostic volatile compounds informing about the composition of Natural Organic Matter (NOM). This knowledge is of large interest as regards monitoring agricultural and environmental dynamic processes. In this communication it is presented an updated overview on recent advances achieved by Analytical Pyrolysis in the structural characterization of NOM. In addition, the application of Py- techniques in practical research on Agricultural and Environmental issues will also be reviewed. In the former case, both the assessment of soil organic matter alterations resulting from different land use and soil management, as well as the transformations of crop residues and compost applied to agricultural lands are amenable to Py-techniques. Concerning the environmental applications, it is to point out the potential of thermodesorption and Py-techniques in detecting the occurrence of pollutants in complex matrices. On the other hand, it is also to mention the success of Py-techniques in monitoring the effects of wildfires on the SOM status. Finally it is also to mention fruitful current research lines such as i) contrasting the quality of the information provided by Py-techniques with the results from classical wet chemical degradation methods, ii) the new information gained from pyrolytic approaches applied to complex macromolecular lipids,and iii)chemotaxonomic assessment of environmental quality, in terms of biodiversity and complexity, based on the multivariate analysis of the pyrolytic compound assemblages from NOM.