oa Discovering Overlooked Biogeochemical Processes through Direct-Infusion Ultrahigh-Resolution Mass Spectrometry

A new workflow using DI ESI FT-ICR MS was developed to screen for organic-solvent-extractable molecular signatures in aquatic ecosystems. The method overcomes the limitations of traditional approaches by requiring only a small sample size and providing a comprehensive view of both known and unknown compounds. By analyzing sediment from various environments, our study identified over 17,000 unique compounds, with 84% being previously uncharacterized. The findings revealed distinct molecular signatures across different environments, showing that estuaries, for example, have unique, less bioavailable signatures that could contribute to carbon burial. The study also highlighted the importance of phosphorus-containing compounds (CHOP), which appear to be influenced by deterministic processes, suggesting their connection to specific metabolic pathways. This untargeted approach offers a powerful initial screening tool for understanding biogeochemical processes in both modern and ancient environments.