Trace determination of mercury by anodic stripping voltammetry at the rotating gold electrode

A simple and highly reliable method for the determination of mercury on a rotating gold disk electrode is reported. The signal is linear with concentration over a wide concentration range (0.2-400 nM). The stability of the electrode is excellent. No mechanical polishing between runs is required and a simple electrochemical pretreatment is applied about once in 100 runs. The detection limit in synthetic solutions, applying the subtractive mode of anodic stripping voltammetry (SASV) is 50 pM for a 120 s deposition time at 5000 rpm and 4 nM in urine sample for 180 s deposition time. The reproducibility of the analytical signal is better than 2% in solutions containing 1 nM Hg(II). The applicability of the method in urine analysis was demonstrated with the use of certified samples. No interference by lead, copper, cadmium, chromium or selenium was found at concentrations corresponding to their toxic occurrence in urine. (C) 2000 Elsevier Science B.V.