Simultaneous application of cloud point and solid-phase extraction for determination of Fe(III) and Cu(II) ions by using SnO₂ nanopowder in micellar medium

Abstract

A new approach was developed for sensitive determination of Fe(III) and Cu(II) ions using SnO₂ nanopowder in the micellar medium on the contrary conventional cloud point extraction studies. The presented method contains a combination of solid-phase extraction and cloud point extraction. According to this procedure, the metal ions were firstly retained on modified SnO₂ nanopowder and then passed to the surfactant-rich phase. The effect of experimental variables including pH, concentration of reagents, eluting solution, incubation time, equilibration temperature, sample volume, and effects of interfering ions have been investigated and optimized systematically. The calibration graphs were linear in the range of 0.23–100.00 μg L⁻¹ and 0.30–110.00 μg L⁻¹ for Fe(III) and Cu(II), respectively. Under optimized conditions, the limits of detections were 0.07 and 0.09 μg L⁻¹ for Fe(III) and 0.09 μg L⁻¹ for Cu(II). The proposed method offers satisfactory analytical features by means of combining two different and efficient preconcentration techniques. In addition, the method can be evaluated as an alternative and fast method according to only-surfactant-mediated extractions. The validation of method was carried out by recovery tests and certified reference material (CRM) analysis. The acceptable and compatible results were obtained in the analysis of CRM and real samples.

Keywords:

• Solid-phase extraction
• Cloud point extraction
• Fe(III)
• Cu(II)
• SnO₂ nanopowder
• Water samples
• Flame atomic absorption spectrometry

Acknowledgment

The authors state their gratitude to Young Researchers and Elite Club in Islamic Azad University for financial support of this work (Grant 1392). A part of pre-experiments was carried out in Analytical Chemistry Research Laboratory at Faculty of Pharmacy in Cumhuriyet University, Sivas, Turkey.