Molecular weight of dissolved organic matter in sediments of the Baltic Sea

Pore water dissolved organic matter average weighted apparent molecular weight (AMW) and abundancies of molecular weight (MW) fractions obtained by Gaussian decomposition of size exclusion chromatograms from pore water samples collected using Rhizon samplers from the water 2 cm above the water-sediment interface and the top 10 cm of the sediment cores at 2cm interval. The sediment cores were recovered using a GeMax sampler. These samples were collected between 2020 and 2021 during cruises onboard RV Oceania (Institute of Oceanology of the Polish Academy of Sciences), which took place in spring, autumn, and winter, to the Central and Southern Baltic Sea, i.e., Eastern Gotland Basin, Bornholm Basin, and Gdansk Basin. The pore water dissolved organic matter molecular weight was used for further evaluation of the sediment flux of dissolved organic carbon. The molecular weight fractionation was used for characterizing pore-water dissolved organic matter in the Baltic Sea sediments.