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Kulichenko, S. A.; Doroshchuk, V. A.

doi:10.1023/a:1024103916725

Cited by 7 publications

(4 citation statements)

References 2 publications

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“…We found previously that basic octylamine species are completely extracted into the micellar OP-10 phase [17]. In this case, the cloud point of solutions reduces to 60 ° C: the solubilization of highly hydrophobic octylamine reduces the hydration of surfactant micelles, and the hydrophilic-hydrophobic balance in the system disturbed by the acid anion is not restored.…”

Section: Resultsmentioning

confidence: 91%

“…Carboxylic acids are characterized by a high extraction capacity due to their good solubility in organic solvents [10]. This property persists in the micellar solutions of nonionic surfactants [11]. The aim of this work was to study the extraction of cadmium with carboxylic acids into nonionic surfactant phases and to select conditions for its atomic absorption determination in natural and waste waters using micellar-extraction preconcentration.…”

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confidence: 99%

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Preconcentration of Cadmium with OP-10 Nonionic Surfactant Phases at the Cloud Point

Doroshchuk

Kulichenko

2005

J Anal Chem

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The micellar extraction of microcomponents with nonionic surfactant phases at the cloud point is one of the most promising analytical applications of organized surfactant media [1,2]. Extraction with nonionic surfactant phases is used for the preconcentration and separation of metal ions, organic toxicants, and biologically active compounds [3]. The advantages of micellar extraction are high absolute preconcentration coefficients for small sample volumes (50-100 mL); easy combination with chromatographic, spectroscopic, electrochemical, and other methods; improved performance characteristics; and a relatively low toxicity of the surfactants used [4][5][6]. In addition, the method is suitable for the effective and selective extraction of hydrophilic and hydrophobic compounds [7].The solubility of nonionic surfactants in water is due to the formation of hydrogen bonds between the oxygen atoms of the surfactant polyoxyethylene chain and water molecules [8]. When aqueous solutions of nonionic surfactants are heated above a specific temperature (cloud point, T c ), these bonds brake and phase separation occurs in the system. As a result, two phases are formed: the micellar phase of a nonionic surfactant composed of coarse hydrated micelles and the aqueous micellar solution of the same surfactant with the concentration close to critical micellation concentration. The micellar phase is used for the preconcentration of microcomponents.Aliphatic monocarboxylic acids and their derivatives are universal extractants; they were proposed for the preconcentration and separation of many metals, including cadmium, a typical anthropogenic environmental pollutant [9,10]. Carboxylic acids are characterized by a high extraction capacity due to their good solubility in organic solvents [10]. This property persists in the micellar solutions of nonionic surfactants [11]. The aim of this work was to study the extraction of cadmium with carboxylic acids into nonionic surfactant phases and to select conditions for its atomic absorption determination in natural and waste waters using micellar-extraction preconcentration. EXPERIMENTAL Reagents and apparatus.Polyoxyethylated alkylphenol OP-10 (Fine Organic Synthesis Plant, IvanoFrankovsk) with the average molecular weight of 647 g/mol, concentration of organic substance >99%, and the average degree of oxyethylation n = 10-12 [12] was used. OP-10 was selected, because it forms a compact and highly viscous nonionic surfactant phase upon heating and the phase formation proceeds more rapidly than that for other nonionic surfactants. OP-10 solutions were prepared by dissolving its portions in distilled water. C n H 2 n + 1 -C 6 H 4 -O-(C 2 H 4 O) m -H ( m = 10-12, n = 8-10).Fatty monocarboxylic acids of the general formula C n H 2 n + 1 COOH of analytical and reagent grade (for liquid and solid acids, respectively) were used. Solid acids were additionally purified by recrystallization from water-ethanol mixtures. Working solutions of acids were prepared by dissolving acid portions in aqueous solut...

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Section: Resultsmentioning

confidence: 91%

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confidence: 99%

Preconcentration of Cadmium with OP-10 Nonionic Surfactant Phases at the Cloud Point

Doroshchuk

Kulichenko

2005

J Anal Chem

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“…[22][23][24][25][26][27][28][29][30][31][32] However, despite the critical importance of Zn 2+ and Cd 2+ monitoring in many industrial, environmental, clinical and pharmaceutical samples, only a few cases of the use of CPE for the separation and preconcentration of Zn 2+ and Cd 2+ have been reported in the literature. [33][34][35][36] In this work, a cloud-point preconcentration procedure was introduced for determination of Zn 2+ and Cd 2+ ions, after the formation of complex with 3,3',3",3'"-tetraindolyl (terephthaloyl) dimethane (TTDM). The lipophilic TTDM-Zn 2+ and Cd 2+ complexes, completely extracted from aqueous solution to the concentrated micellar medium, and the analytes were ultimately analyzed by flame atomic absorption spectrometry.…”

Section: Introductionmentioning

confidence: 99%

Application of cloud point preconcentration and flame atomic absorption spectrometry for the determination of cadmium and zinc ions in urine, blood serum and water samples

Shokrollahi¹,

Joybar²,

Haghighi

et al. 2013

Quím. Nova

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Recebido em 27/3/12; aceito em 20/10/12; publicado na web em 21/2/13 A simple, sensitive and selective cloud point extraction procedure is described for the preconcentration and atomic absorption spectrometric determination of Zn 2+ and Cd 2+ ions in water and biological samples, after complexation with 3,3',3",3'"-tetraindolyl (terephthaloyl) dimethane (TTDM) in basic medium, using Triton X-114 as nonionic surfactant. Detection limits of 3.0 and 2.0 μg L -1 and quantification limits 10.0 and 7.0 μg L -1were obtained for Zn 2+ and Cd 2+ ions, respectively. Relative standard deviation was 2.9 and 3.3, and enrichment factors 23.9 and 25.6, for Zn 2+ and Cd 2+ ions, respectively. The method enabled determination of low levels of Zn 2+ and Cd 2+ ions in urine, blood serum and water samples.

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“…However, despite the critical importance of Zn 2+ monitoring in many industrial, environmental, clinical and pharmaceutical samples, only a few cases of use of CPE for the separation and preconcentration of zinc has been reported in the literature [32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Cloud point extraction-preconcentration and flame atomic absorption spectrometric determination of low levels of zinc in water and blood serum samples

et al. 2009

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A simple, sensitive and selective flotation method is described for the preconcentration and atomic absorption spectrometric determination of zinc ion in water and blood samples. At a solution pH of 5.2, 4-(2-pyridylazo-resorcinol) and Triton X-114 were used as hydrophobic ligand and non-ionic surfactant, respectively. The chemical variables affecting the preconcentration process were optimized. Under the optimized experimental conditions, the selective preconcentration and determination of as low zinc concentration as 6.5 μg L -1 can be made. The proposed method was successfully applied to the preconcentration and low-level determination of zinc in different water and blood serum samples. Warsaw and Springer-Verlag Berlin Heidelberg. © Versita

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Cited by 7 publications

References 2 publications

Preconcentration of Cadmium with OP-10 Nonionic Surfactant Phases at the Cloud Point

Preconcentration of Cadmium with OP-10 Nonionic Surfactant Phases at the Cloud Point

Application of cloud point preconcentration and flame atomic absorption spectrometry for the determination of cadmium and zinc ions in urine, blood serum and water samples

Cloud point extraction-preconcentration and flame atomic absorption spectrometric determination of low levels of zinc in water and blood serum samples

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