Incorporation Onium System with Cloud Point Extraction Method for Extraction and Determination Iron(III) and Mercury(II) in Different Samples (original) (raw)
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A new coupled cloud point extraction (CPE) was developed as prompt, easy and economical preconcentration technique for spectrophotometric determination of tiny amounts of Fe 3+ and Hg 2+ in real samples. A modern thiazolylazo ligand [methyl phenyl thiazolyl azo]-3-methyl-4-methoxy-2-naphthol (MPTAN) was done for the CPE method in the preconcentration of Fe 3+ and Hg 2+ as an earlier step to its characterization by UV-VIS spectrophotometry. The analytical manner includes the formation of under study metals complex with new ligand and quantitatively extracted to the Cloud point layer (CPL) of TritonX-100 after heating. The concentration of MPTAN, metals, pH, thermodynamic data and volume of surfactant was optimized. The investigation of stoichiometry has the ratio of metal to ligand of 1:1. Under finest settings and conditions, the calibration curve was found to be linear in the concentration range of two ions (0.05-10) ppm and the limit of detection for Fe 3+ and Hg 2+ are (0.016 and 0.041) ppm respectively. The suggested CPE has an excellent methodology for characterization of trace metal ions in surrounding samples with a complex matrix as in soils, water, vegetable, meats, and fruits.
Cloud-point extraction/preconcentration on-line flow injection method for mercury determination
Analytica Chimica Acta, 2004
A cloud-point extraction/preconcentration (CPE/P) step is incorporated on-line into a flow injection system which is used to determine low levels of Hg(II) added to natural water samples. The analyte is complexed with dithizone. A solid reagent column (SRC) is used to prepare the reagent on-line by using 5% (v/v) Triton X-100 solution as solvent. The CPE/P is carried out by using the non-ionic surfactant Triton X-100. After obtaining the cloud-point on-line, the surfactant-rich phase containing the complex is collected in a mini column packed with cotton wool. Then, a hot water stream is passed through the column to elute the complex and the absorbance is measured at 500 nm.
Egyptian Journal of Basic and Applied Sciences, 2014
Silver Cloud point extraction Salting-out effect a b s t r a c t A cloud point extraction procedure is proposed for preconcentration of trace amounts of palladium (II), silver (I) and gold (III) in aqueous medium. The metal ions in the initial aqueous solution were extracted using the non-ionic surfactant, Triton X-114 after complex formation with 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide at pH 6.0 in the presence of 0.3 mol L À1 sodium sulfate as a salting-out agent at 25 C. Dilution of the surfactant-rich phase with acidified methanol was performed after phase separation, and the metal ions were determined by electrothermal atomic absorption spectrometry. The main factors affecting extraction procedure, such as pH, concentration of the ligand, and amount of Triton X-114 were studied in detail. Under the optimum experimental conditions, the calibration graphs were linear upto 125, 50 and 100 mg L À1 and the enrichment factors were 52, 46 and 56 for palladium, silver and gold, respectively. The limits of detection, based on three times of standard deviation of blank signal by 10 replicate measurements divided by the slope of calibration curves were 0.12, 0.08 and 0.30 mg L À1 for palladium, silver and gold, respectively. The accuracy of the results was verified by analyzing spiked water samples. The proposed method has been applied for the determination of the metal ions in soil and rock samples with satisfactory results.
Coupling Cloud Point Extraction to Instrumental Detection Systems for Metal Analysis
2006
The purpose of this article is to review and evaluate cloud point extraction of metals and its coupling to different contemporary instrumental methods of analysis. This review covers a selection of the literature published on this topic over the period mainly between 1997 and September 2005 (consisting of 50 publications). The current state of the art for CPE concerning metals and metal chelates is presented with special emphasis on the hyphenation of this interesting extraction=preconcentration approach mediated by surfactants to spectrophotometry, atomic spectroscopy and separation techniques. We present contemporary CPE developments concerning metal speciation and determination and their application to different environmental, clinical, geological and food samples. Strategies for method development as well as future perspectives are also covered.
Water Supply, 2017
A simple, efficient and inexpensive ligandless cloud point extraction method was developed for the preconcentration of trace amounts of iron from natural water samples, followed by flame atomic absorption spectrometry detection. The proposed method is based on the extraction of Fe(III) ions at pH 7.0 using the non-ionic surfactant Triton X-114 without the addition of any chelating ligand. The effect of parameters influencing the extraction efficiency such as sample pH, concentration of surfactant, incubation temperature and time, concentration of NaCl and sample volume were investigated and optimized. The effect of potentially interfering ions on the recovery of iron was also examined. Under optimum conditions, the detection limit (3σ) was 0.95 μg L−1 for Fe using a sample volume of 10 mL. A preconcentration factor of 20 was achieved. The accuracy of the method was checked through the analysis of certified reference materials (SLRS-5 river water, SPS-SW2 Batch 127 surface water) and...
Talanta, 2008
Cloud point extraction (CPE) has been used for the pre-concentration of mercury, after the formation of a complex with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (5-Br-PADAP), and later analysis by electrothermal atomic absorption spectrometry (ETAAS) using polyethyleneglycolmono-p-nonyphenylether (PONPE 7.5) as surfactant. The chemical variables affecting the separation step were optimized. Under the optimum conditions, i.e, pH 8.5, cloud point temperature 80 • C, 5-Br-PADAP = 4 × 10 −5 mol L −1 , PONPE 7.5 = 0.2%, sample volume = 1.0 mL, an enhancement factor of 22-fold was reached. The lower limit of detection (LOD) obtained under the optimal conditions was 0.01 g L −1 . The precision for 10 replicate determinations at 2.0 g L −1 Hg was 4.0% relative standard deviation (R.S.D.). The calibration graph using the pre-concentration system for mercury was linear with a correlation coefficient of 0.9994 at levels near the detection limits up to at least 16 g L −1 . The method was successfully applied to the determination of mercury in biological samples and in certified reference material (QC METAL LL3).
Bulletin of the Chemical Society of Ethiopia
ABSTRACT. For the enrichment of iron(III) prior to spectrophotometric determination, displacement cloud point extraction (D-CPE) technique was applied depending on the difference in stability constant of metal complexes. Zinc(II) as gallic acid complex was first separated into a Triton X-100 surfactant. Then, once the aqueous phase has been removed, the sample containing Fe(III) is added, and another CPE process is performed. Because Fe-GA has a higher stability than Zn-GA, Fe(III) can displace Zn(II) from the pre-extracted Zn-GA, allowing for Fe(III) separation from the complex sample matrix and its spontaneous spectrophotometric determination at 560 nm. The effects of pH, ligand, and surfactant quantities, temperature and heating time, centrifuge processes, and interferences were all studied. At the optimal conditions, the calibration graph was linear from 0.5 to 500 µg L-1 with enrichment factor of 75.0. The LOD was 0.15 µg L-1 and the RSD was 1.3% for 60 µg L-1 of Fe(III), n = 1...
Extracted Zinc as anion from aqueous solution after formation ion pair association complex by cloud point extraction (CPE) method, as well as absorption spectrum demonstrates λ max =414nm for Zinc complex by using laboratory-made azo dye 3-[(2-Pyridyl azo)]-1-nitroso-2-naphthol (PANN) from acidic media of 1M HCl with 1×10-4 M (PANN), 0.6mL Triton X-100, as well as this research involved many studies about effective parameters on extraction efficiency such as thermodynamic and stoichiometry and others. The proposed method applied successfully for spectrophotometric determination of zinc(II) in different samples, D.L= 0.0292 ppm , ε = 70583 L.mol-1 .cm-1 ,Sandell's Sensitivity = 63× 10-9 µg/cm 2. Introduction Possibly consider cloud point extraction method is an indirect method of extraction involved two phases aqueous phase and surfactant after heating these two phases separated by aggregation micelles to form cloud point layer will high density and small volume, the complex formed for zinc distribute between two phases cloud point layer CPL and aqueous solution according to thermodynamic equilibria with help of kinetic law's and to lean on this theory previous study used CPE methodology for extraction Ni (II) as chloroanion by use crown ether DB18C6 from acidic media of 0.5M HCl in presence of 0.25M NaCl and 0.6mL Triton X-100 as well 1×10
Egyptian Journal of Chemistry
A cloud point extraction (CPE) process was described for the separation and spectrophotometric analysis of Fe(III) in different water samples and blood as chelating agent. The complexation reaction between Fe(III) and Zincon was elaborated at pH 5.0 using acetate buffer and the complex was quantitatively recovered in a mixed micelle system composed of cethyltri methyl ammonium bromide (CTAB) and Triton X-114. This reaction was carried out at room temperature in the presence of 0.05 mol L-1 Na2SO4 as salting-out electrolyte. The linearity was up to 1000 µg L-1. The preconcentration factor was 50. The precision (as relative standard deviation) and the limit of detection were 2.5% and 3.1 µg L-1 , respectively. The proposed procedure was used for the spectrophotometric detection of Fe(III) in water and blood samples and the data were statistically comparable to those achieved using ICP-OES technique.
Analytical Sciences, 2007
Cloud point extraction (CPE) has become a very important separation and preconcentration technique for organic compounds 1-3 and inorganic metal ions 4-6 since its introduction in the late seventies. 4,5 Its analytical potential is judged by the increasing number of reviews and publications in the recent literature. 7-11 Most of the nonionic surfactants form micelles in aqueous solution and become turbid when heated to a particular temperature known as the cloud point temperature (CPT). Above this temperature, the micelle solution separates into two transparent liquid phases: a very small volume of surfactant-rich phase at the bottom which is in equilibrium with the bulk aqueous phase containing a surfactant concentration close to its critical micelle concentration. Based on this, efficient extraction and preconcentration schemes can be developed for trace elements with proper selection of chelating agents, which convert them into hydrophobic species (in the aqueous phase). These are adsorbed in the hydrophobic core of the micelles and get preconcentrated in a small volume of surfactant-rich phase. This method provides higher preconcentration factors and it is simple, rapid, safe, and cost effective. Different nonionic surfactants such as Triton X-114 (polyoxyethylene-7.5-octylphenoxy ether), Triton X-100 (polyoxyethylene-9.5-octylphenoxy ether), PONPE (poly nonyl phenyl ether) along with chelating agents such as derivatives of pyridylazo, quinoline, phosphate and carbamate have been most commonly used in CPE. 11-13 The method has been applied for extraction and preconcentration of elements such as Cd; 12 Cu; 14