Molecular-scale investigation on the photochemical transformation of dissolved organic matter after immobilization by iron minerals with FT-ICR MS.

The interaction between dissolved organic matter (DOM) and iron minerals has a significant effect on its stabilization and preservation in the environment. In this study, iron minerals with different crystal forms (crystalline goethite and amorphous ferrihydrite) were selected to investigate the photochemical transformation process for DOM immobilized on iron minerals under simulated sunlight irradiation at the molecular scale with the help of Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The results showed that a total of 7148 molecules were detected in alkaline-extractable sedimentary DOM, of which 38.

Molecular characterization on the fractionation of organic phosphorus induced by iron oxide adsorption using ESI-FT-ICR MS.

The interaction between organic phosphorus (OP) and iron oxide significantly influences the phosphorus cycle in the natural environment. In shallow lakes, intense oxidation-reduction fluctuations constantly alter the existing form of iron oxides, but little is known about their impact on the adsorption and fractionation of OP molecules. In this study, electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS) was used to investigate the fractionation of OP from alkali-extracted sediment induced by crystalline goethite and amorphous ferrihydrite adsorption at a molecular scale.

Changes in sediment greenhouse gases production dynamics in an estuarine wetland following invasion by .

Invasive () has significant impacts on sediment biogeochemical cycling in the tidal wetlands of estuaries and coasts. However, the impact of exotic invasion on greenhouse gases (GHGs) production dynamics in sediments remain limited. Here, we investigated the dynamics of sediment physicochemical properties, GHGs production rates, and microbial gene abundances in a native habitat and three invasive habitats (6-, 10-, and 14-year) in the Minjiang River Estuary, China.