were used to obtain the
extraction systems. The concentration of PEG in polymer-rich
phase was determined from refractive index measurements,
according with the experimental procedure described previously
[28], while the inorganic salt concentration from salt-rich phase
was determined gravimetrically [29]. In each extraction system
certain volumes of heavy metal ions solution (0.5–1.0 mL of
102 mol M(II) L1 solution) and iodide extractant were added.
After addition of all components, the final volume of extraction
system was adjusted to 10 mL with double distilled water.