Table of Contents
ISRN Analytical Chemistry
Volume 2012 (2012), Article ID 705142, 5 pages
http://dx.doi.org/10.5402/2012/705142
Research Article

Spectrophotometric Determination of Gold(III) Using 2-Hydroxy-3-Methoxy Benzaldehyde Thiosemicarbazone as a Chromophoric Reagent

1Department of Chemistry, Sri Krishnadevaraya University, Anantapur 515 003, India
2Department of Chemistry, Vikrama Simhapuri University, Nellore 524001, India

Received 8 March 2012; Accepted 27 March 2012

Academic Editors: A. Bouklouze and R. K. Jyothi

Copyright © 2012 D. Prem Kumar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A chromophoric reagent, 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC), was employed for the sensitive spectrophotometric determination of gold(III). The gold(III) ion forms a blue-coloured complex with HMBATSC in an aqueous dimethyl formamide at pH 6.0. The gold complex shows the absorption maximum at 385 nm, and Beer's law was obeyed in the range 0.49–8.37 μg mL−1. The molar absorptivity and Sandell's sensitivity were found to be 1 . 2 8 × 1 0 4  L mol−1 cm−1 and 0.015 μg cm−2, respectively. The complex shows 1 : 1 [Au(III) : HMBATSC] stoichiometry with a stability constant of 1 . 3 2 × 1 0 6 . The interference effect of various diverse ions has been studied. In addition to zero-order, first- and second-order derivative spectrophotometric methods were also developed for the determination of gold(III) in microgram amounts which were more sensitive than the zero-order method. The developed method has been used for the determination of gold(III) in environmental water samples and certified reference materials. The results were in excellent agreement with the certified values.