The molecular fingerprint of fluorescent natural organic matter offers insight into biogeochemical sources and diagenetic state

• Published in: Analytical Chemistry
• Main Authors: Wünsch, Urban, Acar, Evrim, Koch, Boris Peter, Murphy, Kathleen, Schmitt-Kopplin, Philippe, Stedmon, Colin Andrew
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Arctic
• Online Access: https://orbit.dtu.dk/en/publications/24de4ecc-50b9-4d9c-b99e-1df10ed4213f; https://doi.org/10.1021/acs.analchem.8b02863; https://backend.orbit.dtu.dk/ws/files/161125545/Postprint.pdf

Investigating the biogeochemistry of dissolved organic matter (DOM) requires the synthesis of data from several complementary analytical techniques. In contrast to subjective post-hoc correlation analysis, a robust integration requires data fusion, capable of simultaneously decomposing data from multiple instruments while identifying linked and unrelated signals. Here, Advanced Coupled Matrix and Tensor Factorization (ACMTF) was used to identify the molecular fingerprint of DOM fluorescence fractions in Arctic fjords. ACMTF explained 99.84 % of the variability with six fully shared components. Individual molecular formulas were linked to multiple fluorescence components and vice versa. Molecular fingerprints differed in diversity and oceanographic patterns, suggesting a link to the biogeochemical sources and diagenetic state of DOM. The fingerprints obtained through ACMTF were more specific compared to traditional correlation analysis and yielded greater compositional insight. Multivariate data fusion aligns extremely complex, heterogeneous DOM datasets, and thus facilitates a more holistic understanding of DOM biogeochemistry.