engleski

Physicochemical Signatures of Natural Sea Films from Middle Adriatic Stations

Monolayer studies and force-area quantification approach, in combination with electrochemical methods, are applied for physicochemical characterization of surface active substances (SAS) of the sea surface microlayers (MLs) from Middle Adriatic stations. Higher primary production during late spring-early autumn was reflected in the presence of MLs of higher surfactant activity containing on average molecules of lower molecular masses (Mw=0.65±0.27 kDa) and higher miscibility (y=6.46±1.33) and elasticity (Eisoth=18.33±2.02 mN m-1) modulus in comparison to structural parameters (average Mw=2.15±1.58 kDa ; y=3.51±1.46 ; Eisoth=6.41±1.97 mN m-1) obtained for MLs from period of lower production. Higher inhibition effect on the reduction process of Cd2+ was observed for SAS abundant MLs from more productive period. This kind of distribution is explained as the consequence of competitive adsorption of hydrophobic lipid-like substances of lower Mw that act as end-members, highly influencing the surface structural properties of natural air-water interface forming there segregated surface films during more productive period.

surface active substances; sea surface microlayer; isotherms; surface rheology; organic matter; Adriatic Sea.

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