For obtaining optimized volume of acetonitrile, various experiments were used by using different volumes of acetonitrile (100, 200, 300, 400 and 500 l) containing different volumes of 1-undecanol and all experiments were performed in triplicates. Variation of the volume of acetonitrile causes changes in the volume of the floated phase; hence, it is impossible to consider
the influence of acetonitrile volume on the extraction efficiency. In
order to avoid this and also to achieve a constant volume of the
floated phase, the volume of acetonitrile and 1-undecanol were
changed simultaneously. According to the results in Fig. 3, with
low volumes of the disperser solvent the cloudy state is not formed
satisfactorily and thereby DLLME-SFO procedure is disturbed. On
the other hand, with large volumes of the disperser, the solubil-
ity of analytes in aqueous phase increases and hence the extraction
efficiency
decreases.
Thus,
300
l
of
acetonitrile
was
selected
as
the
volume of disperser solvent in subsequent experiments