ABSTRACT
There are two sources of fatty acids in river water, man-made contamination and naturally occurring. Regarding the latter the determination of free and bound fatty acids present in aquatic systems is important first because fatty acids are sufficiently diverse in structure that they can be used to determine the source and cycling of organic carbon and second because fatty acids in vivo function primarily as structural components of membranes and energy storage products. In the reduced state the amount and type of fatty acids may be indicative of the trophic status of the ecosystem at the time of fatty acid formation. Unsaturated, short chain (≤C20) and microbial fatty acid are indicative of productive systems, whereas long chain acids dominate in oligotrophic systems. Fatty acids have been shown to comprise 5-10 per cent of the weight of humic/fulvic acid structure. As an integral portion of the structure of these refractorymaterials, fatty acids can be used to determine the source of organic carbon and the physical/chemical characteristics of these materials. The behaviour of humic/fulvic acids may determine the transport of toxic trace metals and anthropogenic organics.
