Surfactant cloud point extraction and preconcentration of organic compounds prior to chromatography and capillary electrophoresis

Carabias‐Martínez, Rita; Rodríguez‐Gonzalo, Encarnación; Cordero, Bernardo Moreno; Pavón, José Luis Pérez; Garcı́a-Pinto, C; Laespada, María Esther Fernández

doi:10.1016/s0021-9673(00)00837-2

Cited by 382 publications

(187 citation statements)

References 68 publications

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“…For most non-ionic surfactant, the presence of salts may facilitate phase separation since they increases the density of the aqueous phase [23]. Available electrolytes can also change the cloud point temperatures of non-ionic surfactant.…”

Section: Effect Of Concentration Of Na 2 Somentioning

confidence: 99%

Determination of estrogens in water by HPLC–UV using cloud point extraction

Wang

Cai

et al. 2006

Talanta

134

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A method based on cloud point extraction was developed to determine four kinds of estrogens: estriol (E3), estradiol (E2), estrone (E1), and progesterone (P) in water by high performance liquid chromatography separation and ultraviolet detection (HPLC-UV). The non-ionic surfactant Triton X-114 was chosen as extractant solvent. The parameters affecting extraction efficiency, such as concentrations of Triton X-114 and Na 2 SO 4 , equilibration temperature, equilibration time and centrifugation time were evaluated and optimized. Under the optimum conditions, preconcentration factors of 99 for E3, 73 for E2, 152 for E1 and 86 for P were obtained for 10 mL water sample. The detection of limitation was 0.23 ng mL −1 for E3, 0.32 ng mL −1 for E2, 0.25 ng mL −1 for E1 and 5.0 ng mL −1 for P. The proposed method was successfully applied to the determination of trace amount of estrogens in wastewater treatment plant (WWTP) effluent water and exposure water with 10 ng mL −1 E2 for toxicological study in our lab. For the case of WWTP effluent water samples, no estrogen was found. The accuracy of the proposed method was tested by recovery measurements of spiked samples and good recoveries of 81.2-99.5% were obtained.

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Section: Effect Of Concentration Of Na 2 Somentioning

confidence: 99%

Determination of estrogens in water by HPLC–UV using cloud point extraction

Wang

Cai

et al. 2006

Talanta

134

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“…These solutes may interact electrostatically, hydrophobically or via a combination of both effects. 32 Most analytical chemists have been studying in the field of preconcentration and detection of trace metals. In these studies, organic compounds purchased from chemical production companies are used as complexation reagents.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Bis(amino alcohol)oxalamides and Their Usage for the Preconcentration of Trace Metals by Cloud Point Extraction

et al. 2008

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C2-Symmetric two bis(amino alcohol)oxalamides (diamidediols) were synthesized and fully characterized. A new method was developed and successfully applied for the simultaneous preconcentration of both trace and toxic metals in water, by using C2-symmetric compounds. Under the optimum experimental conditions (i.e. pH = 10.10% w/v octylphenoxy-polyethoxyethanol (Triton X-114)), calibration graphs were linear in the range of 2.5 -25.0 ng mL -1 for Cu and Cd, 5.0 -25.0 ng mL -1 for Co and Ni. The enrichment factors were 18, 23, 18 and 20 for Cd, Cu, Co and Ni in the case of DAD1, respectively; 20, 22, 17 and 20 for Cd, Cu, Co and Ni in the case of DAD2. The limits of detection for DAD1 were found to be 0.45, 0.50, 1.25 and 0.60 ng mL -1 for Cd, Cu, Co and Ni, respectively, and for DAD2 were found to be 0.44, 0.25, 0.60 and 1.55 ng mL -1 for Cd, Cu, Co and Ni, respectively. The developed method was applied to the determination of Cu, Cd, Co and Ni in water samples and certified reference materials with satisfactory results.

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“…packed with a filtering material), and a CL luminometer (Lumiflow LF-800, NITI-ON, Funabashi, Japan). The flow rates for R 2 , R 3 and R 4 .…”

Section: Apparatus and Proceduresmentioning

confidence: 99%

“…The cloud point phase separation behavior of certain surfactants above their critical micelle concentrations (CMC) in aqueous solutions, i.e., the ability of these amphiphiles in forming two apparently immiscible phases -a surfactant-rich (coacervate) phase and a surfactant-dilute, bulk aqueous phase -upon certain conditions (e.g., an increase of the temperature of the micellar solutions above the threshold temperature), was first demonstrated by Watanabe and Tanaka to possess good potential for the rapid and efficient preconcentration of metal ions [1], and cloud point extraction (CPE)-based methodologies are finding increasing usages in the extraction/purification of proteins and other biomolecules [2,3], as well as in the chromatographic analysis of a wide range of organic analytes [4].…”

Section: Introductionmentioning

confidence: 99%