A HYBRID MERCURY FILM ELECTRODE FOR THE VOLTAMMETRIC ANALYSIS OF COPPER AND LEAD IN ACIDIFIED SEAWATER AND OTHER MEDIA

Plating conditions for preparing a consistently reproducible Hg film electrode on a glassy carbon substrate in acid media are evaluated. It is found that a ''hybrid electrode'', i.e., preplated with Hg and then replated with Hg in situ with the sample, gives very reproducible results in the analysis of copper (and lead) in seawater. Consistently reproducible electrode performance allows for the calculation of a cell constant and prediction of the slopes of standard addition plots, useful parameters in the study of copper speciation in seawater.