Impact of Seasonal Climate Change on Optical and Molecular Properties of River Water Dissolved Organic Matter by HPLC

摘要

The dissolved organic matter (DOM) molecular structure and optical parameters change in the natural river water samples from Estonia during two years of winter-spring season where studied. The high performance liquid chromatography (HPLC) method together with multiple-wavelength detection was used for the fractionation of the DOM according to molecular size. The optical characteristics were measured by UV-Vis spectroscopy. The experimental data indicate that optical and molecular properties of DOM depend on climate conditions but the effect can be diverse; in cold climate the concentration of DOM in river water can be lower (2013) or higher (2014) than in warmer climate conditions. Optical properties indicate that the humic substances (HS) concentration is minimal under ice-cover and DOM contains more protein-like (microbial derived) constituents.