Peak Area: the Instrumental Datum to Improve the Determination at Ultratrace Level Concentration of Mercury(II) at Gold Electrode

Abstract

Peak area as instrumental datum for determining the concentration of metals in solution instead of peak height is proposed for analytical voltammetric determinations. In the case of species present at ultra-trace concentration level or having low reversibility degree electrodic processes, the employment of peak area permits to achieve limits of detection lower even more of one order of magnitude. The present work shows the possibility of determining, at ultratrace level concentration, mercury(II) by differential pulse anodic stripping voltammetry (DPASV). The analytical procedure was verified by the analysis of standard reference materials Estuarine Sediment BCR-CRM 277, River Sediment BCR-CRM 320 and Mercury in Water NIST-SRM 1641d and applied to sediments and seawaters sampled in a lagoon ecosystem connected with Adriatic Sea (Ravenna area, Italy). The accuracy, expressed as relative error e (%), and the precision as repeatability, expressed as relative standard deviation s r (%), were satisfactory being lower than 6%. To better validate the analytical procedure, a comparison with spectroscopic measurements is also reported.

Electrochemical Microsensors for the Detection of Cadmium(II) and Lead(II) Ions in Plants

“…Redox signals for cadmium were observed at −0.6 V and for lead at about −0.4 V versus Ag/AgCl 3M KCl. Stripping techniques markedly lowered the detection limits for these ions [ 35 – 42 ]. The metals are preconcentrated by electrodeposition into a small volume mercury electrode.…”