Abstract
Peat humic and fulvic acids were isolated from a surface horizon (0–60 cm) and deeper horizon (>60 cm) of an ombrotrophic peat bog located in Galicia (NW Spain) and which constitutes a record of paleoenvironmental contamination. The humic and fulvic acids were characterized and compared using chemical methods and spectroscopic techniques, including ultraviolet visible (UV-vis), Fourier transform infrared (FTIR) and 13C nuclear magnetic resonance ( 13C NMR). Comparison of the E 4/ E 6 ratios showed that in the deeper horizon the peat humic substances have a greater degree of aromatic condensation than in the surface horizon. The alkyl C content of the humic substances remained practically unchanged, whereas the O–alkyl–C content of humic acids decreased with depth. No variation with depth in the ionization constants of the carboxylic groups or of the phenolic groups was observed. The values of the ratios of the carboxylic/phenolic contents were similar to those reported in the available literature, with a higher content of acid groups in the humic substances isolated from the lower horizon mainly attributable to the carboxylic groups.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
