scholarly journals Development of a Cloud-Point Extraction Method for Cobalt Determination in Natural Water Samples

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Reza Jamali ◽  
Mohammad Gholinezhad ◽  
Saiedeh Balarostaghi ◽  
Reyhaneh Rahnama ◽  
Seyed Hojjat Allah Rahimi
Keyword(s):  
Cloud Point ◽  
Water Samples ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Cobalt Content ◽  
Cobalt Ions ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Triton X

A new, simple, and versatile cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of cobalt. The cobalt ions in the initial aqueous solution were complexed with 4-Benzylpiperidinedithiocarbamate, and Triton X-114 was added as surfactant. Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the cobalt content was measured by flame atomic absorption spectrometry. The main factors affecting CPE procedure, such as pH, concentration of ligand, amount of Triton X-114, equilibrium temperature, and incubation time were investigated and optimized. Under the optimal conditions, the limit of detection (LOD) for cobalt was 0.5 μg L-1, with sensitivity enhancement factor (EF) of 67. Calibration curve was linear in the range of 2–150 μg L-1, and relative standard deviation was 3.2% (c=100 μg L-1;n=10). The proposed method was applied to the determination of trace cobalt in real water samples with satisfactory analytical results.

scholarly journals Cloud point extraction and preconcentration of gold in geological matrices prior to flame atomic absorption determination

2010 ◽  
Vol 8 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Wifky El-Naggar ◽  
Taysseer Lasheen ◽  
El-Said Nouh ◽  
Ahmed Ghonaim
Keyword(s):  
Atomic Absorption ◽  
Cloud Point ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Complexing Agent ◽  
Rich Phase ◽  
Flame Atomic Absorption ◽  
Initial Aqueous Solution ◽  
Triton X

AbstractBrilliant green was used as a complexing agent in cloud point extraction (CPE) and applied for selective preconcentration of trace amounts of gold in geological matrices. The analyte in the initial aqueous solution was acidified with hydrochloric acid (0.1 M) and octylphenoxypolyethoxyethanol (Triton X-114) was added as a surfactant. After phase separation, based on the cloud point separation of the mixture, the surfactant rich phase was diluted with methanol and the analyte determined in the surfactant rich phase by flame atomic absorption spectrometry (FAAS). After optimization of the complexation and extraction conditions, a preconcentration factor of 31 was obtained for only 10 mL of sample. The analytical curve was linear in the range of 3–1000 ng mL−1 and the limit of detection was 1.5 ng mL−1. The proposed method was applied to the determination of gold in geological samples.

scholarly journals MICELLE-MEDIATED EXTRACTION AS A TOOL FOR SEPARATION AND PRECONCENTRATION IN COPPER ANALYSIS

2010 ◽  
Vol 7 (3) ◽  
pp. 278-283
Author(s):  
F. Ahmadia ◽  
A. Khanmohammadi ◽  
A. Malekpour
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Cloud Point ◽  
Flame Atomic Absorption Spectrometry ◽  
Cloud Point Extraction ◽  
Absorption Spectrometry ◽  
Hno3 Solution ◽  
Flame Atomic Absorption ◽  
Separation And Preconcentration ◽  
Triton X

A cloud point extraction method was presented for preconcentration of copper in various samples. After complexation with 4-Amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one (ADPP) or N-Benzoyl-N-phenylhydroxylamine (BPA)  in water, analyte ions are quantitatively extracted to the phase rich in Triton X-114 after centrifugation. 2.0 mol L-1 HNO3 solution in methanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for ADPP, Triton X-114, HNO3 and parameters such as bath temperature, centrifuge rate and time were optimized. Detection limits (3SDb/m) of 1.3 and 1.9 ng mL-1 for ADPP and BPA along with enrichment factors of 30 and 38 for ADPP and BPA were achieved. The high efficiency of cloud point extraction to carry out the determination of analyte in complex matrices was demonstrated. The proposed method was applied to the analysis of biological, industrial, natural and wastewater, soil and blood samples.   Keywords: 4-Amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one (ADPP), N-Benzoyl-N-phenylhydroxylamine (BPA) ,   Cloud Point Extraction, Triton X-114, Flame Atomic Absorption Spectrometry.

Cloud point extraction–flame atomic absorption spectrometry method for preconcentration and determination of trace cadmium in water samples

2014 ◽  
Vol 70 (4) ◽  
pp. 605-611 ◽  
Author(s):  
Jinyan Ning ◽  
Yang Jiao ◽  
Jiao Zhao ◽  
Lifen Meng ◽  
Yaling Yang
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Cloud Point ◽  
Flame Atomic Absorption Spectrometry ◽  
Water Samples ◽  
Cloud Point Extraction ◽  
Absorption Spectrometry ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Trace Cadmium

A method based on cloud point extraction (CPE) separation/preconcentration of trace cadmium (Cd) as a prior step to its determination by flame atomic absorption spectrometry has been developed. Cadmium reacted with 8-hydroxyquinoline to form hydrophobic chelates, which were extracted into the micelles of nonionic surfactant oligoethylene glycol monoalkyl ether (Genapol X-080) in an alkaline medium. Octanol was used to depress the cloud point of Genapol X-080 in the extraction process. The chemical variables that affect the CPE, such as pH of complexation reaction, amount of chelating agent, Genapol X-080 and octanol were evaluated and optimized. Under optimized conditions, linearity was obeyed in the range of 10–500 μg/L, with the correlation coefficient of 0.9993. For 5 mL of sample solution, the enhancement factor was about 20. The limit of detection and limit of quantification of the method were 0.21 and 0.63 μg/L, respectively. The relative standard deviations (n = 6) was 3.2% for a solution containing 100 μg/L of Cd. The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. Recoveries of spiked samples varied in the range of 94.1–103.8%.

Simultaneous preconcentration of cadmium and chromium(III) in water samples by cloud point extraction and their determination by flame atomic absorption spectrometry

2014 ◽  
Vol 70 (12) ◽  
pp. 1913-1918 ◽  
Author(s):  
Lifen Meng ◽  
Jinyan Ning ◽  
Yaling Yang
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Cloud Point ◽  
Flame Atomic Absorption Spectrometry ◽  
Water Samples ◽  
Cloud Point Extraction ◽  
Absorption Spectrometry ◽  
Flame Atomic Absorption ◽  
Relative Standard

A sensitive and simple method for flame atomic absorption spectrometry determination of traces of cadmium and chromium(III) species in water samples after preconcentration by cloud point extraction has been developed. A novel complex agent of alizarin complexone with cadmium (Cd) and chromium (Cr(III)) was quantitatively extracted in surface primary alcohol ethoxylate-rich phase at 33 °C. The effects of experimental conditions including pH of sample solution, concentration of chelating agent and salt, equilibration temperature and time, and foreign ions were evaluated in order to enhance sensitivity of the method. Under optimal conditions, the low limit detections were 6.7 and 3.2 μg/L, and the enrichment factors were 24 and 20 for Cd and Cr(III), respectively. The relative standard deviations were 3.8 and 2.5% for Cd and Cr(II), respectively (n = 11). The high recoveries of the spiked Cd and Cr(III) ions were obtained in the range of 90–116%. The proposed method has been successfully applied for the determination of Cd and Cr(III) in water samples.

Selective Ligandless Cloud Point Extraction of Palladium from Water and Dust Samples

2015 ◽  
Vol 98 (1) ◽  
pp. 201-205 ◽  
Author(s):  
Sayed Zia Mohammadi ◽  
Mohsen Mohammadnezhad
Keyword(s):  
Cloud Point ◽  
High Efficiency ◽  
Cloud Point Extraction ◽  
Absorption Spectrometry ◽  
Ionic Surfactant ◽  
Solution Ph ◽  
Flame Atomic Absorption ◽  
Separation And Preconcentration ◽  
Triton X

Abstract In this study, the phase-separation phenomenon ofnon-ionic surfactants was used for separation and preconcentration of Pd(II). The cloud point extraction(CPE) method is based on the formation of PdI2 which is then entrapped in the non-ionic surfactant Triton X-114. Ethanol acidified with 0.5 M HNO3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry. The main factors affecting CPE efficiency, such as sample solution pH, concentration of iodide ion and Triton X-114, equilibration temperature and time, were all investigated and optimized. At optimum conditions, a calibration curve was constructed for the determination of palladium according to the ligandless CPE procedure. Linearity was maintained between 1.0 to 500.0 ng/mL. The LOD based on three times the SD of the blank divided by the slope of analytical curve, (3Sb/m) was 0.3 ng/mL. Seven replicatedeterminations of a solution containing of 4.0 μg palladium gave a mean absorbance of 0.359 with RSD ±1.85%. The high efficiency of CPE to carry out the determination of palladium in complex matrixes was demonstrated. The proposed method has beenapplied to the determination of trace amounts of palladium in a platinum-iridium alloy, water, and dust samples, with satisfactory results.

scholarly journals Optimization of cloud point extraction procedure with response surface methodology for quantification of iron by means of flame atomic absorption spectrometry

2013 ◽  
Vol 78 (1) ◽  
pp. 115-127 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Abdolhossein Naseri ◽  
Golamhossein Sadeghi
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Cloud Point ◽  
Flame Atomic Absorption Spectrometry ◽  
Cloud Point Extraction ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Ionic Surfactant ◽  
Flame Atomic Absorption ◽  
Relative Standard

A simple micelle-mediated phase separation method has been developed for the pre-concentration of trace levels of iron as a prior step to determination by flame atomic absorption spectrometry (FAAS). The method is based on the cloud point extraction (CPE) of iron using non-ionic surfactant polyethyleneglycolmono-p-nonylphenylether (PONPE 7.5) without adding any chelating agent. Several variables affecting the extraction efficiency were studied and optimized utilizing central composite design (CCD) and three levels full factorial design. Under the optimum conditions, the limit of detection (LOD), limit of quantification (LOQ) and pre-concentration factor were 1.5 ?g L-1, 5.0 ?g L-1 and 100, respectively. The relative standard deviation (RSD) for six replicate determinations at 50 ?g L?1 Fe(III) level was 1.97%. The calibration graph was linear in the rage of 5-100 ?g L-1, with a correlation coefficient of 0.9921. The developed method was validated by the analysis of two certified reference materials and applied successfully to the determination of trace amounts of Fe(III) in water and rice samples.

scholarly journals Determination of cobalt in water samples by atomic absorption spectrometry after pre-concentration with a simple ionic liquid-based dispersive liquid-liquid micro-extraction methodology

2010 ◽  
Vol 8 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Hossein Abdolmohammad-Zadeh ◽  
Elnaz Ebrahimzadeh
Keyword(s):  
Ionic Liquid ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Water Samples ◽  
Limit Of Detection ◽  
Absorption Spectrometry ◽  
Experimental Conditions ◽  
Flame Atomic Absorption ◽  
Relative Standard

AbstractA rapid dispersive liquid-liquid micro-extraction (DLLME) methodology based on the application of 1-hexylpyridinium hexafluorophosphate [C6py][PF6] ionic liquid (IL) as an extractant solvent was applied for the pre-concentration of trace levels of cobalt prior to determination by flame atomic absorption spectrometry (FAAS). 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) was employed as a chelator forming a Co-PMBP complex to extract cobalt ions from aqueous solution into the fine droplets of [C6py][PF6]. Some effective factors that influence the micro-extraction efficiency include the pH, the PMBP concentration, the amount of ionic liquid, the ionic strength, the temperature and the centrifugation time which were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enrichment factor were 0.70 µg L−1 and 60, respectively. The relative standard deviation (RSD) for six replicate determinations of 50 µg L−1 Co was 2.36%. The calibration graph using the pre-concentration system was linear at levels 2–166 µg L−1 with a correlation coefficient of 0.9982. The applicability of the proposed method was evaluated by the determination of trace amounts of cobalt in several water samples.

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