Abstract

COMPLEX FORMATION IN A LIQUID-LIQUID EXTRACTION SYSTEM CONTAINING NICKEL (II), 2,6-DITIOL-4-ETYLPHENOL AND BATHOPHENANTROLINE

Kuliev K. A.*, Verdizade N. A., Aliev S. G., Suleymanova G. S. and Mamedova Sh. A. Efendieva N. N.

Abstract

Complex formation and liquid-liquid extraction were studied in a system containing nikel(II), 2,6-ditiol-4-etylphenol (DTEP), bathophenantroline (BPhen), water, and chloroform. The effect of some experimental parameters (pH, shaking time, concentration of DTEP, and concentration of BPhen was systematically investigated, and the optimum conditions for nickel extraction as an ion-association complex, Ni(DTEP) (BPhen)2, were found. The following key equilibrium constants were calculated: constant of stability (lg𝛽 = 19.08), constant of distribution (log𝐾D = 2.09 ± 0.01), and constant of extraction (lg𝐾ex = 18.67). Beer’s law was obeyed for Ni concentrations up to 16 𝜇g × mL−1 with a molar absorptivity of 2.83 x 104 L mol−1 cm−1 at 𝜆max = 475 nm. Some additional characteristics, such as limit of detection, limit of quantification, and Sandell’s sensitivity, were estimated as well.

Keywords: Spectrophotometry; nickel(II), 2,6-ditiol-4-etylphenol, water, chloroform.