Nickel and cobalt determination in the North Western Mediterranean by differential pulse cathodic stripping voltammetry

Differentiai pulse cathodic stripping voltammetry can be applied to sea water with high sensitivity for nickel and cobalt analysis (limits of detection about 0.005 and 0.002 j.lg L 1 respectively) using the dimethylglyoxime complexes. At concentrations of 0.200 j.lg Ni L -l and 0.050 j.lg Co L 1 the standard deviations for replicate analyses were 8% and 2% respectively. The linearity of the calibration curve derived during the method of standard additions was ± 5% for Ni and ± 1% for Co. Analysis of water from North Western Mediterranean Sea profiles gave Ni levels of 0.207 ±0.043 Jlg L 1 and Co levels of 0.006±0.003 Jlg L 1• The metallevels found accorded closely with those reported by other authors in different oceans.