ABSTRACT
CONTENTS 17.1 Classification of Aquatic Organic Matter ................................................................... 435
17.1.1 Organic Main Categories ................................................................................. 435 17.1.2 Particle Size Distribution ................................................................................. 436
17.2 Determination of Organic Carbon ............................................................................... 438 17.2.1 CO2 Method....................................................................................................... 438 17.2.2 UV-Vis Spectroscopy ....................................................................................... 440 17.2.3 Fluorescence Spectroscopy .............................................................................. 441
17.3 Characterization of Dissolved Organic Carbon......................................................... 442 17.3.1 Chromatographic Methods with Different Resins ...................................... 442 17.3.2 High-Performance Size-Exclusion Chromatography.................................. 444
References ................................................................................................................................... 447
17.1.1 Organic Main Categories
Aquatic natural organic matter (NOM) is found in water systems of all types, oceans, and freshwaters including groundwater areas. Clear evidence of its presence is the characteristic yellow-brown color of a bog or swamp water and many lakes and rivers. Even ‘‘clean’’ waters, such as those from certain deep lakes, open oceans, or even deep ground waters, contain at least a small fraction of the aquatic NOM-typical concentrations being within the range of ca. 1 to 3 mg L1. Accordingly, the aquatic NOM is one of the largest pools of carbon on the Earth.
