Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.orggeochem.2020.104165
Title (Primary) Multi-proxy approach involving ultrahigh resolution mass spectrometry and self-organising maps to investigate the origin and quality of sedimentary organic matter across a subtropical reservoir
Author Sartori Jeunon Gontijo, E.; Herzsprung, P.; Lechtenfeld, O.J. ORCID logo ; de Castro Bueno, C.; Barth, J.A.C.; Rosa, A.H.; Friese, K. ORCID logo
Source Titel Organic Geochemistry
Year 2021
Department SEEFO; ANA
Volume 151
Page From art. 104165
Language englisch
Topic T5 Future Landscapes
T9 Healthy Planet
Data and Software links https://doi.org/10.17632/r86jr7x6dz.1
Supplements https://ars.els-cdn.com/content/image/1-s2.0-S014663802030200X-mmc1.docx
Keywords Kohonen neural network; 13C NMR; FT-ICR-MS; Stable isotopes; Humic substances; Source discrimination
UFZ wide themes ProVIS;
Abstract Humic substances (HS) in sediments play an important role in carbon and nutrient biogeochemical cycles and fate of contaminants in the environment. However, information regarding HS quality and transformations that may affect their behaviour in reservoirs is still limited. The aim of this investigation was to track sources and changes in sedimentary HS across a subtropical reservoir, connecting them to in-lake processes and land-use influences. Surface sediments were collected at seven sampling sites in Itupararanga Reservoir (Brazil). Humic (HA) and fulvic (FA) acids (components of HS) were extracted from the sediment samples followed by in-depth characterisation via UV/VIS, fluorescence spectroscopy, elemental (C, N) and isotopic analysis (δ13C, δ15N), nuclear magnetic resonance (13C NMR) and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). All data were analysed by self-organising maps. The results showed that samples from the upstream part of the reservoir were older and more decomposed. They likely originated from C3 land-plants (δ13C varied from −26.3‰ to −22.4‰), having more aromatic, oxygen-poor (O/C < 0.5) and unsaturated compounds (H/C < 1.1). In contrast, near-dam samples were younger and had larger contributions of autochthonous material. This was confirmed by oxygen-rich (O/C > 0.5) and partly more unsaturated compounds for FA as well as oxygen-poor and saturated compounds with H/C > 1.1 for HA. Self-organising maps pointed out these differences between upstream and dam areas and indicated that agriculture lands were related to microbially-derived HS. Changes in HS composition revealed that internal reservoir processes may have influenced HS quality across the reservoir.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=24010
Sartori Jeunon Gontijo, E., Herzsprung, P., Lechtenfeld, O.J., de Castro Bueno, C., Barth, J.A.C., Rosa, A.H., Friese, K. (2021):
Multi-proxy approach involving ultrahigh resolution mass spectrometry and self-organising maps to investigate the origin and quality of sedimentary organic matter across a subtropical reservoir
Org. Geochem. 151 , art. 104165 10.1016/j.orggeochem.2020.104165