Cloud Point Extraction and Flame Atomic Absorption Spectrometry Determination of Lead (II) in Environmental and Food Samples (original) (raw)
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CLEAN - Soil, Air, Water, 2009
The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of lead(II) and zinc(II). After complexation with 3-[(4bromophenyl) (1-H-inden-3-yl)methyl]-1 H-indene (BPIMI), the analytes were quantitatively extracted to a phase rich in Triton X-114 after centrifugation. Methanol acidified with 1 mol/L HNO 3 was added to the surfactant rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of bis((1H-benzo [d] imidazol-2yl)ethyl)sulfane, Triton X-114, pH and amount of surfactant were all optimized. Detection limits (3 SDb/m) of 2.5 and 1.6 ng/mL for Pb 2+ and Zn 2+ along with preconcentration factors of 30 and an enrichment factor of 32 and 48 for Pb 2+ and Zn 2+ ions were obtained, respectively. The proposed cloud point extraction was been successfully applied for the determination of these ions in real samples with complicated matrices such as food and soil samples, with high efficiency.
Arabian Journal of Chemistry, 2011
A sensitive cloud point extraction procedure(CPE) for the preconcentration of trace lead prior to its determination by flame atomic absorption spectrometry (FAAS) has been developed. The CPE method is based on the complex of Pb(II) ion with 1-(2-pyridylazo)-2-naphthol (PAN), and then entrapped in the non-ionic surfactant Triton X-114. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of PAN and Triton X-114, equilibration temperature and time, were investigated in detail. A preconcentration factor of 30 was obtained for the preconcentration of Pb(II) ion with 15.0 mL solution. Under the optimal conditions, the calibration curve was linear in the range of 7.5 ng mL À1 -3.5 lg mL À1 of lead with R 2 = 0.9998 (n = 10). Detection limit based on three times the standard deviation of the blank (3S b ) was 5.27 ng mL À1 . Eight replicate determinations of 1.0 lg mL À1 lead gave a mean absorbance of 0.275 with a relative standard deviation of 1.6%. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated.
Journal of AOAC International
(BIMMBI) are quantitatively extracted into the Triton X-114-rich phase after centrifugation. A solution of 1.0 M HNO 3 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 HNO 3 , 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 Pb 2+ , Ag + , and Zn 2+ , respectively, along with a preconcentration factor of 30 and enrichment factors of 33, 48, and 53 for Pb 2+ , Ag + , and Zn 2+ , 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.
Journal of Physical & Theoretical Chemistry, 2018
2-(3indolyl) – 4,5 di phynyl imidazole.(IDPI) was used as a complexing agent in cloud point extraction for the first time and applied for selective pre-concentration of trace amounts of cadmium. The method is based on the extraction of cadmium at pH= 7.0 by using non-ionic surfactant TritonX114 and 2-(3indolyl) – 4,5 di phynyl imidazole. (IDPI) as a chelating agent. The adopted concentrations for IDPI, Triton X-114 and HNO3, bath temperature were optimized, The response are linear over concentration range of 8.0-90 (ng mL -1 ) for Cd 2+ and RSD % (n =5) 1.8 for Cd 2+ , Detection limits (3SDb/m, n =10, m = slope of calibration) of 2.8 (ng.mL -1 ) for Cd 2+ respectively. The enrichment factors was 33 for Cd 2+ . the preconcentration factors was 39 for Cd 2+ respectively. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed method was successfully applied to the ultra-trace determination of cadmium i...
Eurasian Journal of Analytical Chemistry, 2017
A simple, sensitive and feasible cloud-point extraction (CPE) methodology has been developed for the separation and preconcentration of cadmium and lead ions in real samples. The metals in the aqueous solution were complexes with 2-(3indolyl) 4,5 di phynyl imidazole.(IDPI), at pH = 7.0 and Triton X-114 was added as surfactant. The variables effecting like concentration of Triton X-114 and HNO3, bath temperature, centrifuge rate and time on the cloud-point extraction were optimized. Under optimum conditions, the response are linear over concentration range of 0.025-1.3(μg mL-1) for Cd2+, 0.064-1.27(μg mL-1) for Pb2+ andRSD % (n =5) 1.4 for Cd2+, 1.3 for Pb2+, detection limits (3SDb/m, n =10, m = slope of calibration) of 0.15 (μg.mL-1) for Cd2+ and 0.13 (μg.mL-1) Pb2+ respectively. The enrichment factors were 31 for Cd2+ and 37 for Pb2+. The preconcentration factors were 26 for Cd2+ and 31 for Pb2+ respectively.
Pakistan Journal of Analytical & Environmental Chemistry, 2011
The proposed method is based on the complexation of the Pb2+, Cd2+ and Pd2+ ions with 3-(1-(1-H-Indol-3-Yl)-3-phenylallyl)-1H-indole (IPAI) at pH 8.0 in the presence of Triton X-114. The phase separation occured when micellar solution was heated at 55 ◦C. The surfactant-rich phase, diluted to 0.5 mL via 1.0 mol L−1 nitric acid in methanol was directly introduced into the nebulizer of the flame atomic absorption spectrometry (FAAS). Influence of variables such as pH, amount of ligand and Triton X-114, heating time and temperature were evaluated and optimized. The optimized enhancement factors for Pb2+, Cd2+ and Pd2+ ions were 22, 33 and 23, respectively and the detection limit (DLs) was between of 1.6–2.6 µgL−1. The relative standard deviation (RSD) of each ion was found to be less than 4.6% at 100 µgL−1. In addition, the calibration graphs were linear in the range of 0.01-0.22 μg mL−1 for Cd2+ ion, 0.018-0.26 μg mL−1 for Pb2+ ion and 0.02-0.27 μg mL−1 for Pd2+ ion with the correlati...
Determination of cadmium(II) ion by atomic absorption spectrometry after cloud point extraction
Journal of the Iranian Chemical Society, 2012
In this work, cloud point extraction (CPE) technique was developed for the separation and pre-concentration of Cd(II). CPE was used with lipophilic hexadentate (N 4 O 2 ) Schiff base ligand, L 22pysa (1, C 24 H 26 N 4 O 2 ). The methodology is based upon the formation of a Cd(II)/L complex soluble in a micellar phase the non-ionic surfactant Triton X-114. This complex is then extracted into the surfactant-rich phase above its cloud point temperature. Several important variables that affect the CPE were investigated and optimized. Under the optimum experimental conditions, the calibration graph was linear over the range 1-100 ng mL -1 with a correlation coefficient of 0.9997. The detection limit obtained under optimum conditions was 0.44 ng mL -l . The proposed method was successfully applied to the determination of Cd(II) in rice and various water samples.
Bulletin of Faculty of Science, Zagazig University, 2019
A new, cost-effective, and environmental-friendly cloud point extraction methodology was described for enrichment of lead and cadmium in real water samples. The method involves the complexation of lead or cadmium with 2-nitro-6-(1,3-thiazol-2-diazeyl)-phenol at pH 8.5 and 7.0 for cadmium and lead, respectively, then extraction into Triton X-114. After dilution of the surfactant-rich phase with acidified methanol, the enriched analytes concentration was estimated by spectrophotometric measurements at 590 and 540, respectively. Parameters that influenced cloud point extraction, such as pH, reagent, surfactant and nitric acid concentrations, centrifuge rate and time, temperature, incubation time, as well as interferences were evaluated and optimized. The preconcentration factor was 50 and the detection limits were 1.64 and 1.62 µg L-1 for lead and cadmium, respectively. The method presented relative standard deviation as precision were 2.28% and 1.96% for lead and cadmium, respectively. The accuracy of the new preconcentration procedure was checked by the analysis of the standard reference materials, and successfully applied to determine lead and cadmium in real water samples with relative recovery values in the range of 95.40%-101% for the spiked samples.
Acta Periodica Technologica
A Cloud point extraction (CPE) procedure was presented for preconcentration of lead(II) ions, after complexation by 18-crown-6 (18C6) and extraction with Triton X-100 at proposed experimental conditions. After separation of surfactant - rich phase, content of Pb(II) ions in remaining solution was measured by Flame Atomic Absorption Spectrometry (FAAS). The experimental conditions such as pH, temperature, concentration of Triton X-100, concentration of 18C6, incubation time, type and concentration of added electrolyte, were evaluated. Results showed that among investigated electrolytes (NaCl, Na2SO4 and Na2CO3) the amount of 0.9 mol/L Na2CO3 lowers cloud point temperature of Triton X-100 to 22?C (room temperature during the experiment), thus simplifying the extraction procedure. After an incubation time of 5 minutes and using the concentration of 1.2?10-3 mol/L Triton X-100 and 1.5?10-4 mol/L 18C6 (1:1 stoichiometric ratio for 18C6:Pb), 60% of lead (II) ions were efficiently removed ...
Central European Journal of Chemistry, 2009
A 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 HNO 3 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 HNO 3, 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 Cu 2+ , Fe 3+ , Ni 2+ and Zn 2+ along with preconcentration factors of 30 and enrichment factor of 48, 39, 34 and 52 for Cu 2+ , Ni 2+ , Fe 3+ and Zn 2+ 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.