Direct Determination of Trace and Sustrace Metals in Natural Waters by Dpasv. The Use of Long-Lasting Sessile-Drop Mercury Electrodes Compared to Commercial Hanging-Drop Mercury Electrodes (Kemula Type)

Abstract

Abstract The performance of a new kind of semi-stationary mercury electrode (i.e., LLSDME) is compared to that of some commercially available Kemula electrodes (Metrohm and Tacussel HMDE) in the direct determination of metals at trace and subtrace levels by DPASV technique. The results obtained in the stripping analysis of a pure electrolyte solution as well as of sea-water samples, show that a LLSDME offers better reproducibility, better sensitivity and hence lower detection limit (down to 50 ng/1), Moreover, using HMDE with Silicone-coated capillaries (necessary for a HMDE when testing a solution containing surface-active substances) still poorer sensitivity and reproducibility were obtained.