Buletinul Institutului Politehnic din Iași Secția Chimie și Inginerie Chimică ISSN: 2537-2947
ISSN-L: 0254-7104
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
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.