Dissolved organic carbon content

Gershey et al. [58] concluded that a continuous and automated photooxidation procedure of the type described by Collins and Williams [30], with the reported modifications, will probably satisfy most of the needs of the oceanographer concerning measurement of dissolved organic carbon. The convenience and rapidity of the method opens up a new area of research the study of the small-scale temporal and spatial variations of the dissolved organic carbon content of the oceans. 

Driscoll et al. (1994) have studied the mercury species relationships among water, sediments, and fish (yellow perch) in a series of Adirondack lakes in New York state, USA. In most lakes, approximately 10% of the total mercury loading was in the form of C2HsHg+. Mercury concentrations increased as pH fell, but the best correlation was found between [dissolved Al] and [dissolved Hg] suggesting that the same factors are responsible for mobilizing both these metals. Methylmercury concentrations correlated strongly with the dissolved organic carbon content in the water. Fish muscle tissue was analyzed for mercury and showed an increase with age. However, the study was unable to resolve the question of whether the principal source of mercury to these lakes was atmospheric deposition or dissolution from bedrock due to acid rains. 

Gamier, C., Mounier, S., and Benaim, J. Y. (2004). Influence of dissolved organic carbon content on modelling natural organic matter acid-base properties. Water Res. 38, 3685-3692. 

Dissolved organic carbon content does, however, appear to influence the release of atrazine from soil (Clay and Koskinen, 1990a Liu et al., 1995), with more released in the presence of dissolved organic content. Fulvic acid in... 

Bioavailable concentrations of metals depend on various parameters, including pH, Ca and Mg concentrations, as well as dissolved organic carbon content. Hence, measuring these parameters in parallel with the metals can assist with interpretation of results where appropriate. In case of cadmium, the measurement of hardness is mandatory because EQS values have been derived for five classes of hardness. 

Mercury was detectable in the tissues of almost all freshwater fishes examined, with the majority of the mercury (>80-99%) present as methylmercury. Methylmercury is absorbed more efficiently than inorganic mercury from water, and probably from food, and is retained longer regardless of the uptake pathway. Three important factors modifying mercury uptake in aquatic organisms are the age of the organism, water pH, and the dissolved organic carbon content. In fish, for example, mercury tends to accumulate in muscle tissues of numerous species of freshwater and marine fishes and to... 

The algal extract used contained 73 Xg/mL of microcystin-LR and a dissolved organic carbon content of 2200 pg/mL. The organic matter present in addition to microcystin-LR was presumably a complex mixture of algal exudates. 

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