Flotation separation of cobalt and copper from fresh waters and their determination by electrothermal atomic absorption spectrometry

A rapid flotation method for cobalt and copper separation and enrichment fr om fresh waters is established. At pH 6.0, ionic strength of 0.02 mol/l, us ing sodium dodecylsulfate as a foaming reagent, cobalt and copper were sepa rated simultaneously with 10 mg Fe(III) and 3 x 10(-4) mol hexamethylenedit hiocarbamate (HMDTC-) added to 1 l of aqueous solution. Iron(III) hexamethy lenedithiocarbamate, Fe(HMDTC)(3), is used as a new additional flotation co llector. The proposed procedure of preconcentration is applied before elect rothermal atomic absorption spectrometric (ETAAS) determination of these tw o analytes. The method is verified by comparison of the ETAAS results with inductively coupled plasma-atomic emission spectrometric measurements (ICP- AES). The limit of detection for cobalt is 0.0012 mu g/l, while for copper it is 0.0120 mu g/l. (C) 2000 Elsevier Science B.V. All rights reserved.