MICRO-COULOMETRIC DETERMINATION OF TRACE AMOUNTS OF MERCURY AND OXYGEN IN AQUEOUS-SOLUTIONS USING THE HANGING MERCURY DROP ELECTRODE (HMDE)

The microcoulometric method of indirect determination of oxygen and mercury using anodic stripping voltammetry has been developed. The experiments have been carried out with solution of 0.1 M KNO3, 10-4 M HNO3 with additions of Hg(II) and O2, using small concentrations of Cu(II) as inner standard. It was found that the method is suitable for the determination of oxygen and of mercury ions in the concentration range of 10-7-10-6 M. Traces of mercury ions and oxygen in the deaerated solutions are probably the main cause of difficulties in the stripping analysis of metal ions below 10-7 M. © 1979 Elsevier Sequoia S.A.