Analytical non-discriminating pyroly-sis in soil analysis

摘要

Pyrolysis and tetramethyl ammonium hydroxide (TMAH)-induced thermochemolysis are widely used in soil analy-sis as fast,sensitive and reproducible techniques to release diagnostic fragments from large organic mole-cules.Conventional experimental approaches share the common shortcoming of discriminating against high boil-ing analytes,which often carry the most significant struc-tural information.Non-discriminating pyrolysis,based on capacitive discharge heating of deactivated stainless steel capillaries containing the samples,enables the analysis of some of these diagnostic targets in the soil humic organic network,thus revealing some of the "soil carbon we do not see" that is often cited.The technique is capable of detecting high boiling point surrogates of the soil lipid fraction along with markers of soil microbial communities (e.g.sterols,hopanes,terrestrial fatty acids beyond approx C_(22),etc.),which could not be detected unam-biguously by conventional analytical pyrolysis up till now.