A developed cloud point extraction method for Tl(III) determination by flame atomic absorption spectrometry

ABSTRACT

Tl(III) was extracted and preconcentrated using cloud point extraction (CPE) for its determination in water samples using flame atomic absorption spectrometry (FAAS). The CPE procedure was performed using a non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) as an extractant at room temperature in the presence Br⁻ or I⁻. Tl(I) was oxidized in presence of bromine water to T(III) to form Tl(Br)₃ complex which then was extracted into the surfactant-rich phase. The factors influencing the CPE such as sample pH, concentrations of bromide and iodide ions and Triton X-114 were studied. After optimisation of CPE conditions, the preconcentration factors were found 74 for Br₂ and 68 for KI, the limits of detection (3 s) were 5.7 and 8 ng mL⁻¹ for Br₂ and KI, respectively. The relative standard deviation (RSD) was 3.7% for Br₂ and 2.6% for KI. The results showed that the proposed method was free from interference. The CPE method was successfully used for Tl(III) determination in real samples.

KEYWORDS:

• Thallium
• Triton X-114
• cloud point extraction
• determination
• flame atomic absorption

Disclosure statement

No potential conflict of interest was reported by the authors.