Original scientific paper

Polarography of Marine Particles: A Model Study

Nadica Ivošević ; Ruđer Bošković Institute, Center for Marine Research, P.O.B. 1016, 10001 Zagreb, Croatia
Vera Žutić ; Ruđer Bošković Institute, Center for Marine Research, P.O.B. 1016, 10001 Zagreb, Croatia

Abstract

A simple polarographic method for direct measurement of surface active constituents of seawater was used to investigate the effect of variable levels of dissolved surfactants on the detection of attachment signals of surface active particles at the artificial interface.
A mixture of dextran solutions and dispersion of insoluble squalene droplets simulates electrochemical signals in natural samples and allows prediction of the behaviour of natural organic particles.
For the same distribution of particles in the aqueous dispersion, attachment signals frequency decreases exponentially with an increasing bulk concentration of dissolved molecules. Attachment rate of particles at the dropping mercury electrode (DME) depends on the extent of surface coverage with adsorbed molecules (0). At full coverage of the electrode, no particle attachment signals can be detected.
The actual distribution of surface active particles can be determined by direct measurement of attachment signals when 6 < 0.5, which is the case of the majority of seawater samples. For 6 ž 0.5, dilution with organic free electrolyte and/or sampling within the initial part of the DME life-time should be used.

Keywords

Hrčak ID:

135612

URI

https://hrcak.srce.hr/135612

Publication date:

3.4.1997.

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