The volume of the dispersive solvent is an important parameter in DLLME because,
at small volumes, the dispersion
of the extraction solvent does not occur and the cloudy solution
is not formed. On the other hand, the use of large volumes
increases the solubility of the extraction solvent (and analyte)
in the aqueous phase, decreasing the extraction efficiency.23
After dispersive (acetonitrile) and extraction (tetrachloroethylene)
solvents have been chosen, experiments were
performed to evaluate the volume of these solvents. The
volume of acetonitrile ranged from 200 to 1500 μL in
combination with 50 μL of C2Cl4 and 500 μL of 1% (m/v)
APDC at pH 3.3. As can be seen in Figure 3, Fe recovery
increased according to the increase of acetonitrile volume up to
1300 μL. A significant difference (Tukey−Kramer test)
between 1300 and 1500 μL of acetonitrile was not observed,