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

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.

2010 ◽  
Vol 7 (3) ◽  
pp. 278-283
Author(s):  
F. Ahmadia ◽  
A. Khanmohammadi ◽  
A. Malekpour

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.


2009 ◽  
Vol 7 (1) ◽  
pp. 148-154 ◽  
Author(s):  
Mehrorang Ghaedi ◽  
Ardeshir Shokrollahi ◽  
Khodabakhsh Niknam ◽  
Ebrahim Niknam ◽  
Mustafa Soylak

AbstractA cloud point extraction procedure for the preconcentration of copper, nickel, iron and zinc ions in various samples has been described. Analyte ions in aqueous phase are complexed with 3-((indolin-3-yl)(phenyl)methyl)indoline (IYPMI) and following centrifugation quantitatively extracted to the aqueous phase rich in Triton X-114. The surfactant-rich phase was dissolved in 2.0 mol L−1 HNO3 in methanol prior to metal content determination by flame atomic absorption spectrometry (FAAS). The effects of some parameters including, the concentrations of IYPMI, Triton X-114 and HNO3, bath temperature, centrifuge rate and time were investigated on the recoveries of analyte ions. At optimum conditions, the detection limits of (3 SDb m−1) of 1.6, 2.8, 2.1 and 1.1 ng mL−1 for Cu2+, Fe3+, Ni2+ and Zn2+ along with preconcentration factors of 30 and enrichment factor of 48, 39, 34 and 52 for Cu2+, Ni2+, Fe3+ and Zn2+ respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as biological, soil and blood samples with high efficiency.


2009 ◽  
Vol 92 (3) ◽  
pp. 907-913 ◽  
Author(s):  
Mehrorang Ghaedi ◽  
Ardeshir Shokrollahi ◽  
Khodabakhsh Niknam ◽  
Ebrahim Niknam ◽  
Somayyeh Derki ◽  
...  

Abstract A cloud point extraction (CPE) procedure was presented for the preconcentration of silver, zinc, and lead ions in various samples. The complexes of these metal ions with 2-(((1H-benzo[d]imidazol-2-yl)methoxy)methyl)-1H-benzo[d]imidazole (BIMMBI) are quantitatively extracted into the Triton X-114-rich phase after centrifugation. A solution of 1.0 M HNO3 in methanol was added to the surfactant-rich phase as the effective eluant before analysis by flame atomic absorption spectrometry. The influence of effective parameters such as the concentrations of BIMMBI, Triton X-114, and HNO3, pH, bath temperature, centrifuge rate, and time on method sensitivity and efficiency was optimized. Detection limits of 2.8, 1.7, and 1.1 ng/mL for Pb2+, Ag+, and Zn2+, respectively, along with a preconcentration factor of 30 and enrichment factors of 33, 48, and 53 for Pb2+, Ag+, and Zn2+, respectively, were obtained. The present CPE method is suitable for accurate and precise determination of trace amounts of analyte ions in complex matrixes. The proposed CPE procedure was applied to the determination of these ions in biological, natural water, wastewater, soil, and blood samples.


2014 ◽  
Vol 6 (10) ◽  
pp. 3241-3246 ◽  
Author(s):  
Zonghao Li ◽  
Jiaxi Chen ◽  
Mousheng Liu ◽  
Yaling Yang

A new method based on ultrasound-assisted cloud point extraction (UA-CPE) using the mixture of non-ionic surfactant alkylphenol ethoxylate NP-7 and alkylphenol ethoxylate NP-9 for the preconcentration of trace amounts of lead (Pb) and cadmium (Cd) in water samples prior to determination by FAAS has been developed.


2013 ◽  
Vol 96 (2) ◽  
pp. 447-452 ◽  
Author(s):  
Naeemullah ◽  
Tasneem G Kazi ◽  
Faheem Shah ◽  
Hassan I Afridi ◽  
Jameel Ahmed Baig ◽  
...  

Abstract A simple method for the preconcentration of cadmium (Cd) and nickel (Ni) in drinking and wastewater samples was developed. Cloud point extraction has been used for the preconcentration of both metals, after formation of complexes with 8-hydroxyquinoline (8-HQ) and extraction with the surfactant octylphenoxypolyethoxyethanol (Triton X-114). Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the Cd and Ni contents were measured by flame atomic absorption spectrometry. The experimental variables, such as pH, amounts of reagents (8-HQ and Triton X-114), temperature, incubation time, and sample volume, were optimized. After optimization of the complexation and extraction conditions, enhancement factors of 80 and 61, with LOD values of 0.22 and 0.52 μg/L, were obtained for Cd and Ni, respectively. The proposed method was applied satisfactorily for the determination of both elements in drinking and wastewater samples.


2009 ◽  
Vol 6 (s1) ◽  
pp. S33-S40 ◽  
Author(s):  
F. Ahmadi ◽  
A. Khanmohammadi ◽  
Z. Tavakoli

Cloud point extraction (CPE) has been used for preconcentration of copper after the formation of a complex with 5, 5-diphenylimidazolidine-2-thione-,4-one (thiophenytoin) (DFID) and later analysis by flame atomic absorption spectrometry (FAAS) using octylphenoxypolyethoxyethanol (Triton X-114) as surfactant. The chemical variables affecting the separation phase and the viscosity affecting the detection process were optimized. At pH 5.7±0.3, preconcentration of only 15 mL of sample in the presence of 0.06% (w/v)Triton X-114 and 1.5 mM DFID permitted the detection limits of 1.5 ng mL−1for copper. The enrichment factor was 39 for copper. The proposed method has been applied to the determination of copper in various samples and a standard reference material.


2010 ◽  
Vol 8 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Wifky El-Naggar ◽  
Taysseer Lasheen ◽  
El-Said Nouh ◽  
Ahmed Ghonaim

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.


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