Measurements of trace concentrations of mercury in sea water by stripping chronopotentiometry with gold disk electrode: influence of copper

A stripping chronopotentiometric method, using a rotating gold disk electro de for mercury measurements in sea water is described. Compared with a same method using a stationary gold film electrode, this method has a eight tim es higher sensitivity and a detection limit of 5 ng l(-1) after 10 min depo sition time. Moreover, the time needed for gold plating is eliminated. Comp ared with other electrochemical methods capable of measuring mercury at low concentrations, the present method is more simplified with no degassing st ep and no need to use a medium-exchange procedure before the stripping step . These characteristics render the method easily practicable on board ocean ographic vessels for 'in situ' measurements. (C) 2000 Elsevier Science B.V. All rights reserved.