Thermal Lens Spectroscopy for Quantitative Determination of a Cu(II) Complex With an 8-Aminoquinoline Derivative in Tap Water and Mining Wastewater Samples Using a Dual Beam Technique

Abstract

This article describes the quantitative determination of Cu(II) using thermal lens spectrometry. The chromogenic reaction involving Cu(II) and 5-(4-sulphophenylazo)-8-aminoquinoline in alkaline solution was studied in different experimental conditions such as pH, ligand concentration, methanol volume, and presence of interfering ions. A collinear dual beam set-up has been used for direct quantitation in water samples without a pre-concentration step. The optimized conditions provided a linear calibration in the concentration range from 3.0 to 15.0 × 10⁻⁷mol L⁻¹. The detection and quantitation limits were 6.13 × 10⁻⁸ and 2.04 × 10⁻⁷mol L⁻¹, respectively. Resultantly, an application to Cu(II) determination in tap water (recovery 99.8–103.3%) and mining (synthetic) wastewater (95.3–98.0%) shows relative SDs ≤ 3.1%. The method is presented as a new alternative for the direct Cu(II) determination in real samples.

Keywords:

• Aminoquinolines
• metals
• tap water
• thermal lens spectroscopy
• wastewater

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grant FONDECYT 1161132. The authors are also thankful to Dr G. Olivares-Rentería for her valuable help in proofreading the article.