2024, Volume 70(74), Issue 1 (January), pp. 23 - 34

Quantitative Spectrophotometric Determination of Au(III) Ions in Aqueous Solution with Basic Violet 10 Dye

BIANCA-MARIA HĂISAN, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iaşi, Romania
ALEXANDRA-GEORGIANA APOSTICĂ, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iaşi, Romania
LAURA BULGARIU, “Gheorghe Asachi” Technical University of Iaşi, “Cristofor Simionescu” Faculty of Chemical Engineering and Environmental Protection, Iaşi, Romania, lbulg@ch.tuiasi.ro

pages 23 - 34   Download
DOI: 10.5281/zenodo.11145069
Abstract
Spectrophotometric determination of Au(III) ions with Basic Violet 10 dye is a rapid, sensitive and accurate method that can be used in quantitative analysis. The colour reaction occurs immediately in acidic aqueous solution (pH = 0, HCl solution), and this represents an important advantage from a practical point of view. The qualitative parameters of coloured Au(III)-complex (maximum wavelength (500 nm), width of the spectral band (120 nm) and molar absorption coefficient (2.55·104 L·mol-1·cm-1)) suggest the possibility of using this reaction in quantitative analysis. Lambert-Beer’s law was obeyed in the Au(III) concentration range of 0.4 – 2.0 mg·L-1, while the detection limit and limit of quantification were found to be 0.067 mg·L-1 and 0.22 mg·L-1. This colour reaction is quite selective for Au(III) ions in the presence of some interfering ions (Cu(II), Zn(II), Na(I)), while other metal ions (such as Ca(II), Mg(II), Co(II)) interfere to a great extend. The measurements performed using tap water as a background, showed that there are significant differences between the concentration of Au(III) ions, added and calculated from the calibration curve, which limits the applicability of this method in the analysis of real samples.
Keywords: Spectrophotometric method; Au(III) ions; Basic Violet 10; quantitative analysis.