Fatty-acid composition of dissolved and particulate matter in surface films

Lipids containing fatty acids, together with other surface-active substances, can form continuous films on the sea surface. Owing to the complex structures of fatty acids, they are suitable for use as tracers in investigations of the origin and fate of surface films.Surface films were sampled west of the island of Sylt from the 20th to 22nd of August, 1974. After filtration, the fatty-acid composition of the chloroform-soluble part was analyzed in the particulate and dissolved fractions, respectively. Thereby different types of surface films could be characterized, which varied in total quantity, as well as in the relative amounts of fatty acids in the filtrate and particulate matter.It is plausible that such fatty acids will accumulate at surfaces which are chemically stable, as e.g. the saturated fatty acids, which are more resistant to photolytic and chemical degradation than their unsaturated counterparts.The fatty-acid patterns changed as soon as the film contained a large amount of particulate lipids, which shows correlations to the dissolved surface-active substances. Thus, correlations between the fatty-acid pattern in the surface film and that of Prorocentrum micans could be determined.