A rapid stripping potentiometric method for the determination of trace levels of manganese in seawater and industrial waste waters has been developed. The analysis is performed in the presence of oxygen with an analysis time of less than 2.5 min per sample at manganese concentratioris lower than 5pg/L. The precision of the method is satisfactory and the results for 5 seawater and waste water samples compare favorably with graphite furnace atomic absorption spectrophotometry.

A rapid and highly sensitive method using constant current stripping potentiometry for the determination of nickel and cobalt in seawaters and industrial wastewaters has been established. The method is based on the adsorptive accumulation of nickel and cobalt in the presence of either dimethylglyoxime (DMG) or or-benzyldioxime (a-BD) prior to stripping using a constant reducing current. Nitrite is used in the stripping step for the catalytic enhancement of the stripping signal. Analytical protocols for standard solutions using DMG or a-BD show good precision (RSDs between 3 and 4% on the same film) and detection limits (30ng/L for Ni/DMG; IOng/L for Co/DMG; 9ng/L for Co/cu-BD). However, iron interferes significantly with the determination of cobalt using a-BD. With DMG, the simultaneous determination of nickel and cobalt is possible and has been developed into a protocol readily applicable to the routine determination of these metals. The analytical protocol is rapid, easy to perform and the results are in agreement with those obtained by graphite furnace atomic absorption spectrophotometry. The DMG procedure has also been optimized for the determination of cobalt alone, which has advantages for determinations at concentrations of 1 pg/L or less.