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P-ISSN: 2349-8528, E-ISSN: 2321-4902   |   Impact Factor: GIF: 0.565 NAAS Rating: 5.31 NEW

International Journal of Chemical Studies

Vol. 5, Issue 4 (2017)
Extraction-spectrophotometric study of ternary complexes of Cr (VI) using O-Hydroxythiophenols and Aminophenol


Author(s): Rafiga K Mamedova, Sultan G Aliyev, Novrasta S Hasanova, Nailya A Verdizadeh and Ali Z Zalov

Abstract: The o-hydroxythiophenols was synthesized and an extractive spectrophotometric method was developed for determination of Cr (III) at microgram level by using 0.1M HCl solution. Mixed-ligand complexes of Cr (III) with HTPD and Am have been studied by spectrophotometry. The optimal conditions for the formation and extraction of mixed-ligand compounds have been found. Extraction of mixed ligand complexes is maximal at pH 3.0-5.0. The molar ratio of the reacting Cr (III), HTPD and Am species is 1:3:3. For the formation and extraction of MLC, a 26-30-fold excess of complexing reagents is required {1.0×10-3 M HTPD and (1.12-1.16) ×10-3 M Am}. A large excess of hydrophob amin interferers with the determination. However it was found that the presence of excess of the reagent solution does not alter the absorbance of the color reaction. Unlike single-ligand complexes, mixed-ligand complexes of Cr (III) with HTPD and Am were stable in aqueous and organic solvents and did not decompose for two days, or over a month after extraction. The required duration of the phase contact was 15 min. The molar absorptivity of the complex was calculated with Komar method to be ε= (3.1-3.3)×104 L mol-1 cm-1. The general formula of the ternary complexes is They can be regarded as ion-associates between three charged anionic chelates [Cr(HTPD)3]3- and protonated Am species. The made calculations showed that MLC in an organic phase won't be polymerized and are in a monomeric form (γ =1.09-1.15). The adherence to Beer’s law was studied by measuring the absorbance value of the series of solutions containing different concentrations of the metal ion. A linear calibration graph drawn between absorbance and the metal ion concentration indicates that Cr(III) may be determined in the range 0.5-20.0 𝜇g/ml. Method is rapid, selective, reproducible and reliable. The method is applicable for determination of Cr (III) in the steel and soil samples. The results obtained are in good agreement with the certified values and comparable to those obtained by known methods. The method is eco-friendly, as extraction is carried out in pH medium and has good potential for its use in the determination of Cr (III) after extraction in organic phase at microgram level.

Pages: 1255-1262  |  413 Views  12 Downloads

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How to cite this article:
Rafiga K Mamedova, Sultan G Aliyev, Novrasta S Hasanova, Nailya A Verdizadeh, Ali Z Zalov. Extraction-spectrophotometric study of ternary complexes of Cr (VI) using O-Hydroxythiophenols and Aminophenol. Int J Chem Stud 2017;5(4):1255-1262.
International Journal of Chemical Studies