Homogeneous Liquid-liquid Extraction for thePreconcentration of Copper Using a New Schiff Baseand Determination in Water Samples by Flame AtomicAbsorption Spectrometry

In this study, a simple and effective homogeneous liquid-liquid extraction method was applied for extraction and determination of Cu2+ after formation of complex with a new SchifFs base N,N-bis(diacetylmonoxim)-naphthylene-1,8-diimine using (water/tetrabutylammonium ion (TBA)/chloroform) as a ternary component system and the later was determined by flame atomic absorption spectrometry (FAAS). The phase separation phenomenon occurred by an ion-pair formation of TBA and perchlorate ion. Then sedimented phase was separated using a 100 μl micro-syringe and diluted to 1.0 ml with ethanol. The sample was introduced into the flame by conventional aspiration. After the optimization of complexation and extraction conditions such as pH=8.0, [ligand]=1.0 x 104 mol I/1, [TBA]= 2.0 x 10 2 mol L-1 [CIO4] = 2.0 x 10-2 mol L-1 and 100 0 |iL of CHC13, a preconcentration factor (Va/Vs) of 100 was obtained for only 10 ml of the sample. The limit of detection was sufficiently low and lie at ppb level. The proposed method was applied for the extraction and determination of Cu2+ in natural water samples with satisfactory results. The relative standard deviation was 2.5 % (n=10). Accuracy and application of the method was estimated by using test samples of natural and synthetic water spiked with different amounts of copper (II) ion. The method is very simple and inexpensive.