Preconcentration and matrix isolation of heavy metals through a two-stage solvent extraction in a flow system

摘要: Abstract Metal ions (Cd, Cu, Pb, Co and Ni) in trace amounts were isolated from sample matrices concentrated by extraction a flow system. The was first mixed with buffer reagent (carbamates) the combined aqueous next segmented trichlorotrifluoroethane (Freon 113). metal complexes extracted into organic phase 2-m long coil which followed separator teflon membrane. passed on to second segmentor where an acidic, mercury(II) solution added. Back-extraction took place 1-m coil. Freon removed membrane collected analyzed graphite-furnace atomic absorption spectrometer. enrichment factors of order 15–20 recoveries 90–100% sub-μg l −1 level up 20–50 μg . decrease at concentrations above 50 , presumably because slow dissolution precipitated solutions. observed for copper generally somewhat lower, being range 80–90%.