Cloud point extraction for the determination of copper, nickel and cobalt ions in environmental samples by flame atomic absorption spectrometry

• Published in: Journal of hazardous materials Vol. 150; no. 3; pp. 533 - 540
• Main Authors: Ghaedi, M., Shokrollahi, A., Ahmadi, F., Rajabi, H.R., Soylak, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 11-02-2008; Elsevier
• Subjects: Animals; Applied sciences; Cacao; Candy - analysis; Cattle - blood; Centrifugation; Centrifugation, cyclones; Chemical engineering; Cloud point extraction; Cobalt - analysis; Cobalt - blood; Cobalt - chemistry; Copper - analysis; Copper - blood; Copper - chemistry; Environmental Monitoring; Environmental Pollutants - analysis; Environmental Pollutants - blood; Environmental Pollutants - chemistry; Exact sciences and technology; Flame atomic absorption spectrometry; Fresh Water - analysis; General purification processes; Hydrogen-Ion Concentration; Liquid-liquid and fluid-solid mechanical separations; Liver - chemistry; Methanol - chemistry; Methyl-2-pyridylketone oxime (MPKO); Nickel - analysis; Nickel - blood; Nickel - chemistry; Oximes - chemistry; Pollution; Polyethylene Glycols - chemistry; Pyrazoles - chemistry; Sodium Chloride - chemistry; Soil - analysis; Spectrophotometry, Atomic; Spinacia oleracea - chemistry; Surface-Active Agents - chemistry; Temperature; Triton X-114; Wastewaters; Water Supply - analysis; Water treatment and pollution; Methyl-2-pyridylketone oxime (MPKO); Cloud point extraction; Flame atomic absorption spectrometry; Triton X-114; Centrifuge; Complexation; Clouds; Extract; Surfactant; Nitric acid; Blood; Flame spectrometry; Waste water; Enrichment factor; Detection limit; Preconcentration; Basic medium; Atomic absorption spectrometry
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2007.05.029

A cloud point extraction procedure was presented for the preconcentration of copper, nickel and cobalt ions in various samples. After complexation with methyl-2-pyridylketone oxime (MPKO) in basic medium, analyte ions are quantitatively extracted to the phase rich in Triton X-114 following centrifugation. 1.0
mol
L
−1 HNO
3 nitric acid in methanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for MPKO, Triton X-114 and HNO
3, bath temperature, centrifuge rate and time were optimized. Detection limits (3
SDb/m) of 1.6, 2.1 and 1.9
ng
mL
−1 for Cu
2+, Co
2+ and Ni
2+ along with preconcentration factors of 30 and for these ions and enrichment factor of 65, 58 and 67 for Cu
2+, Ni
2+ and Co
2+, respectively. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed procedure was applied to the analysis of biological, natural and wastewater, soil and blood samples.