Preconcentration by cofiotation for the polarographic determination of traces of heavy metals in water

摘要

Preconcentration by coflotation is employed to improveudthe detection limits for the determination of parts perudbillion levels of heavy metal ions such as copper(II),udlead(lI), cadmium(II), zinc(II), nickel(II) and coba1t(II) in natural and sea water by differential pulse polarographyud(DPP). Trace amounts of these ions in water areudcoprecipitated on colloidal aluminium hydroxide and theudprecipitate is floated with the aid of sodium oleate and audstream of nitrogen bubbles. Experimental conditions areudoptimized to obtain maximum recovery of these ions byudcofiotation. The effect of surfactant on the DPP peakudcurrents of these ions in 'the supporting electrolyte used in this work is studied.