Lipophilic organic seawater concentrates

Lipophilic organic compounds in seawater usually occur at minute concentrations. The high sensitivity of modem analytical instruments would, in principle, permit analyses of the amounts present in small volume water samples. However, contamination of the sample by substances adhering to the surfaces of water samplers or laboratory glassware, by solvents, reagents, gases, etc., becomes a severe problem at ultratrace levels of analytes usually present in seawater. 

Technical grade preparations of mirex consists of 95.19% mirex and less than 2.58 x 10 % contaminants, mostly kepone CioClioO. Mirex is comparatively soluble in various organic solvents, such as benzene, carbon tetrachloride and xylene, with solubilities ranging from about 4000.0 to 303,000.0 mg/L. However, mirex has a very low solubility in water, not exceeding 1.0(xg/L in freshwater or 0.2 xg/L in seawater. In biological systems, mirex lipophilicity would account for the high concentrations observed in fatty tissues and reserves. 

The most conspicuous organic contaminants of seawater are organochlorine compounds (Broman et al., 1991), fossil hydrocarbons and their oxidation products Ehrhardt and Bums, 1993), linear alkylbenzenes, alkylphenols (Marcomini et al, 1990 Blackburn and Waldock, 1995), and phthalate esters Waldock, 1983). Concentration procedures for these lipophilic substances are described here. However, the analyst should be aware of the fact that contaminants are not the only lipophilic chemicals likely to be present in seawater. A large number of recently biosynthesised, as well as man made chemicals not listed above, will also be concentrated by these methods. 

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