Determination of copper(II) by flame atomic absorption spectrometry after its perconcentration by a highly selective and environmentally friendly dispersive liquid–liquid microextraction technique

Journal of Analytical Science and Technology

Table 2 Results of investigation of the effect of the ratio of volume of the sedimented phase to volume of ethanol (diluting solvent) on the analytical signal of Cu(II) determined by DLLME

Volume of sedimented phase (μL)	Added volume of chloroform (μL)	Added volume of ethanol (μL)	A _Cu
50	0.0	150	0.106
50	20	130	0.104
50	40	110	0.107
50	60	90	0.105
50	80	70	0.104

Conditions: sample volume, 10.0 mL; Cu(II), 50.0 μg L⁻¹; solution pH = 2.0; salophen, 2.0 × 10⁻⁵ M; disperser solvent (acetone) volume, 1.30 mL; diluting solvent, ethanol; centrifuge time, 5 min (at 5000 rpm)