Hydrocarbons in sea water

From the inventories drawn up on natural and anthropogenic hydrocarbons in the marine environment, it is possible to arrive at an estimate of the bulk of natural hydrocarbons present in the oceans. From various estimates (Button, 1971 Farrington and Meyers, 1975), it would seem that the amount of natural hydrocarbons present in the marine environment exceed the estimated petroleum input. 

With the exception of coastal or polluted areas, the majority of the values obtained for dissolved and particulate hydrocarbon concentrations lie within the range of 1 to 50 jug 1 (Table I, section 2). The data show a general trend for the concentrations to increase near the surface and particularly in the surface microlayer higher levels are found in inshore and productive coastal waters. 

Confirming the data of Blumer (1970), the isolation of n-alkanes ranging from about C,4 to C36 without predominance of odd over even carbon number compounds was noticed by several authors for example, Parker et al. (1972) for unfiltered surface samples from the Gulf of Mexico and the Carribean sea, Barbier et al. (1973) for filtered samples of coastal waters off the French coast and open waters from the eastern Atlantic Ocean, Iliffe and Calder, (1974) for filtered samples from the eastern Gulf of Mexico loop current and the Carribean Sea, Hardy et al. (1977b) for waters collected around the United Kingdom, and Saliot and Tissier (1977) for the Norwegian Sea. 

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Jensen S, Rosenberg R. 1975. Degradability of some chlorinated aliphatic hydrocarbons in sea water and sterilized water. Water Res 9 659-661. 

Goebel R., Krska R., Kellner R., Katzir A., Development of Protective Polymer-Coatings for Silver-Halide Fibers and Their Application as Threshold Level Sensors for Chlorinated Hydrocarbons in Sea-Water, Fresenius J. Anal. Chem. 1994 348 780-781. 

Roy, G., R. Vuillemin, and J. Guyomarch. 2005. On-site determination of polynuclear aromatic hydrocarbons in sea water by stir bar extraction (SBSE) and thermal desorption (GC-MS). Talanta 66 540-546. 

Several other factors may influence the solubility of hydrocarbons in sea water water temperature, salinity and the presence of certain types of organic compounds such as fulvic or humic acids (Boehm and Quinn, 1973 Sutton and Calder, 1974,1975 Eganhouse and Calder, 1976). 

Dawson, R. and Ehrhardt, M., 1976. Determination of aromatic hydrocarbons in sea water. In K. Grasshoff (Editor), Methods of Sea Water Analysis. Verlag Chemie, Wein-heim, pp. 227—234. 

Saliot, A. (1981) Chapter 11, Natural hydrocarbons in sea water, in Marine Organic Chemistry, vol. 31 (eds E.K. Duursma and R. Dawson), Elsevier Oceanography Series, pp. 327-374. 

Muller, D.G. (1979) Olefinic hydrocarbons in sea-water signal molecules for sexual reproduction in brown algae. Pure Appl. Chem., 51,1885-1891. 

Table 5. Representative concentrations of chlorinated hydrocarbons in sea waters [34,40,43, 51]...

Walker et al. [84] examined several methods and solvents for use in the extraction of petroleum hydrocarbons from estuarine water and sediments, during an in situ study of petroleum degradation in sea water. The use of... 

Boehm, P.D. and Quinn. J.G. Solubilization of hydrocarbons by the dissolved organic matter in sea water, Geochim. Cosmochim. Acta, 37(ll) 2459-2477. 1973. 

Chet I, Mitchell R. 1976. Petroleum hydrocarbons inhibit decomposition of organic matter in sea water. Nature 261(5558) 308-309. 

Walker et al. [114] examined several methods and solvents for use in the extraction of petroleum hydrocarbons from estuarine water and sediments, during an in situ study of petroleum degradation in sea water. The use of hexane, benzene and chloroform as solvents is discussed and compared, and quantitative and qualitative differences were determined by analysis using low-resolution computerised mass spectrometry. Using these data, and data obtained following the total recovery of petroleum hydrocarbons, it is concluded that benzene or benzene-methanol azeotrope are the most effective solvents. 

Polycyclic aromatic hydrocarbons, -alkanes, alcohols, aldehydes, ketones, fatty acid esters and phthalates were quantified in sea water samples taken at various depths under the pack ice in Terra Nova Bay and in the Ross Sea (Wood Bay)... 

Picer M, Picer N. 1993. Evaluation of modification o the simple spectrofluorimetry method for estimating petroleum hydrocarbon levels in sea water. Bull Environ Contam Toxicol 50(6) 802-810. 

The very extensive use and high consumption of chlorinated hydrocarbons in plant protection resulted in a contamination of the whole environment. DDT (l,l,l-trichloro-2,2-bis(p-chlorophenyl)ethane) is very dangerous on account of its toxic effects on all the living organisms. It is remarkably resistant, and its residence time in the atmosphere is considered to be several decades. Due to its method of its application, the atmosphere serves as its largest reservoir. Its vapour pressure at 273 K is 2 x 10 Pa, which represents about 3 fig m. This concentration would correspond to a total amount in the troposphere of roughly 10 t. The other estimate is lower by about one half. From the atmosphere, it is removed only by the rain and the great majority is then transported into the oceans. It is nearly insoluble in sea water but is soluble in fats and thus, it is accumu-... 

Zirino, A. and Yamamoto, S., 1972. A pH-dependent model for the chemical speciation of copper, zinc, cadmium and lead in sea water. Limnol. Oceanogr., 17 661—671. Zsolnay, A., 1977. Inventory of non-volatile fatty acids and hydrocarbons in the oceans. Mar. Chem., 5 465—475. 

Techniques for the collection, storage, conservation, isolation and analysis of hydrocarbons from sea water and sediment are briefly described below and illustrated in Fig. 1. Typical data and descriptions of the techniques employed for the analysis of natural or mixed hydrocarbons firom sea water or sea surface microlayers from coastal and open sea areas considered to be relatively unpolluted, are given chronologically in Table I. 

Extraction of dissolved hydrocarbons from sea water Most of the methods used are based on the liquid—liquid extraction of lipids by a solvent various solvents such as CH2CI2, CHCI3, CQ4, nCeHn, nCsHi2, petroleum ether and ethyl acetate have been tested for the recovery and employed (Table I). Recovery of a synthetic mixture of saturated hydrocarbons by extraction with petroleum ether and ethyl acetate is about 97% (Jeffrey et al., 1964). Blumer (1970) demonstrated that the extraction of dissolved lipids at pH 2 using pentane as the solvent was quantitative after four extraction steps. Parker et al. (1972), using a technique for the continuous extraction from sea water with hexane, found in control experi-... 

Many of the hydrocarbons have small but measurable solubilities in water. Data obtained by Sutton and Calder (1974) indicate that normal paraffins are less soluble in sea water than in distilled water (for example 0.8 compared with 1.1 )ng r for the n-C2o). This plays a significant role in the estuarine environment. If the river water is saturated with respect to normal paraffins, salting out will occur in the fresh water/sea water mixing zone and salted-out molecules may be adsorbed onto mineral or organic particles. So, estuaries may act to limit the amount of dissolved molecules and may increase the amount of particulate organic carbon entering the ocean (Sutton and Calder, 1974). 

Blumer, M., 1970. Dissolved organic compounds in sea water saturated and olefinic hydrocarbons and singly branched fatty acids. In D.W. Hood (Editor), Organic Matter in Natural Waters. Inst. Mar. Sci., Alaska, Occas. Publ., No. 1 153—167. 

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