engleski

Constant current chronopotentiometric stripping characterization of organic matter in seawater from the northern Adriatic, Croatia

Catalytically active polysaccharides (Cat PSs) and nitrogen-containing polymeric organic material (N- POM) were determined in seawater from the northern Adriatic station ST101. Catalytically active organics were measured by applying electrochemical methods of adsorptive transfer chronopotentiometric stripping (AdT CPS) with medium exchange and chronopotentiometric stripping (CPS) in unmodified seawater. Their concentrations were expressed in mg dm-3 of equivalents of the model calibrating substances, polysaccharide xanthan and protein human serum albumin (HSA), respectively. The optimal electroanalytical conditions for determination of Cat PSs in seawater were evaluated and defined. Seasonal changes of Cat PSs and N-POM were observed during the period 2011–2013. The highest values were determined in the spring/summer period and the lowest in winter. Cat PSs and N-POM were present in both the dissolved and particulate organic carbon fractions. Cat PSs and N-POM showed a statistically significant positive correlation with the concentrations of surface-active substances (SAS). A weak but statistically significant correlation was found between Cat PSs and dissolved organic carbon (DOC) concentrations. Copper complexing capacities (CuCC) in the period 2011–2013 were in the range 41–130 nmol dm-3.

analytical chemistry ; marine chemistry ; environmental biopolymers ; environmental colloids

Special issue: Voltammetry in environmental chemistry.