ИСТИНА

Dissolved organic matter (DOM) is present in all types of natural water and constitutes a significant reservoir of organic carbon in coastal zones. Since the cromophoric DOM (CDOM) absorbs UV light and emit luminescence, its spectral-optical properties are widely used in ecological monitoring of natural aquatic environments. The presentation summarizes major CDOM spectral characteristics experimentally measured for various samples (solutions of fulvic acids and humic acids, marine and riverine water, freshwater and relic lakes, oxic-anoxic environments). The utilization of absorbance spectroscopy and differentiation of optical densities for CDOM characterization and discrimination from other chromophoric materials in water is described. Special attention is made for dependencies of emission wavelength and fluorescence quantum yield on the wavelength of exciting radiation. The dependencies of fluorescence characteristics on wavelength of excitation are discussed from the point of view of CDOM source and its structural composition.