EXTRACTIVE DETERMINATION OF Zn(II) AND Cd(II) IN INDUSTRIAL SAMPLES USING 1, 5- DIMETHYL-2-PHENYL-4[(E)-2,3,4- TRIHYDROXY PHENYL)]DIAZENYL-1,2-DIHYDROXYL-3H-PYRAZOL-3-ONE, (H3L).

Abstract

as a tetradentate ligand to Zn(II) and Cd(II) to form [Zn(H2L)2] and [Cd(H2L)2] respectively. The ligand was characterized by 1H and 13C NMR, Infrared and UV spectroscopy whereas the complexes were characterized via UV and IR spectroscopy as well as conductivity and mole ratio determinations. Extractive determinations were based on the formation of darkbrown hydrophilic complexes of Zn(II) and Cd(II) by H3L, which are readily extractible into chloroform. Effects of extraction variables like pH, salting –out agents, masking agents and concentration of H+ was studied. Cd(II) was quantitatively extracted in 0.001M HCl up to 100% but masked by 0.001M  of either SCN- or tartrate up to 90% under five minutes. Extraction of Zn(II) with H3L/CHCl3 was also quantitative(96%) in 0.001M HCl within 70 min, but was masked by CN- and SCN- up to 79% and 67% respectively. Cd(II) was successfully separated from Zn(II) in a four cycle extraction in 0.001M HCl using H3L/CHCl3 in the presence of 1M CN-. Recovery of Zn(II) and Cd(II) from rubber carpet following the procedure reached 90% and 85% respectively. Keywords: 1, 5- Dimethyl-2-phenyl-4[(E)-2,3,4- trihydroxyphenyl)]diazenyl-1,2-dihydroxyl-3H-pyrazol-3-one, (H3L), extractive determination of Zn(II) and Cd(II).