3.7. Effect of salt
For investigating the effect of ionic strength on the performance
of DLLME, various experiments were performed
by adding different amounts of NaCl (0–5%). Other experimental
conditions were kept constant. By increasing the ionic
strength (from 0 to 5%) the solubility of extraction solvent
(chlorobenzene) in aqueous phase decreases. Therefore, the
volume of the sedimented phase increases from 5.0 to 6.2 L
and the enrichment factor slightly decreases from 290–900 to
218–741.