Preconcentration and determination of copper and cadmium ions with 1,6- bis(2-carboxy aldehyde phenoxy)butane functionalized Amberlite XAD-16 by flame atomic absorption spectrometry (original) (raw)
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Journal of Hazardous Materials, 2009
Bis(5-bromo-2-hydroxybenzaldehyde)-1,2-propanediimine is synthesized by the reaction of 5-bromo-2hydroxybenzaldehyde and 1,2-diaminopropane in ethanol. This ligand is used as a modifier of octadecyl silica disks for preconcentration of trace amounts of copper(II) ions, followed by nitric acid elution and flame atomic absorption spectrometric (FAAS) determination. The effect of parameters influencing the extraction efficiency, i.e. pH of the sample solutions, amount of the Schiff base, type and volume of stripping reagent, sample and eluent flow rates were evaluated. Under optimum experimental conditions, the capacity of the membrane disks modified by 4 mg of the ligand was found to be 247.7 (±2.1) g of copper. The detection limit and the concentration factor of the presented method are 2.4 ng/l and greater than 400, respectively. The method was applied to the extraction, recovery and detection of copper in different synthetic and water samples.
International Journal of Industrial Chemistry, 2012
Background Oximes are a group of complexing agents with good affinity towards transition metal ions; The major advantages of SPE disks are: faster sample processing due to the high cross sectional area of the disk and decrease in pressure drop, allowing higher sample flow rates; less chance of plugging by particulate matter due to wide bed; reduced channeling and improved mass transfer because of small packing particles. Context and purpose Indane-1,2,3-trione 1,2-dioxime was used as complexing agent for the preconcentration of trace amounts of Cu(II) ions from aqueous samples by modifying octadecyl silica membrane disks prior to determination by flame atomic absorption spectrometry. Results The influence of analytical parameters including pH and flow rate of sample solution, amounts of complexing agent, and type and flow rate of eluent for the stripping of Cu(II) from the disks were investigated. Main findings The proposed method had a linear range of 5.0 to 500 ng mL−1. The limit of detection of the method was 0.2 ng mL−1, and an enrichment factor of 200 was obtained. Conclusion The proposed method has been applied to the determination of copper in several aqueous samples with satisfactory results.
Solid phase extraction of copper(II) ions using C18-silica disks modified by oxime ligands
Journal of Hazardous Materials, 2010
5-Tert-butyl-2-hydroxy-benzaldehyde oxime (L 1) and 3,5-di-tert-butyl-2-hydroxy-benzaldehyde oxime (L 2) are synthesized and characterized by conventional spectroscopic methods. These ligands are used as modifier of octadecyl silica membrane disks for separation and pre-concentration of trace amounts of copper(II) ions, followed by sulfuric or nitric acid elution and flame atomic absorption spectrometric (FAAS) determination. The effect of parameters influencing the extraction efficiency i.e. pH of sample solutions, amount of the oxime, type and volume of eluent, sample solution and eluent flow rates were evaluated. Under optimum experimental conditions, the maximum capacity of the membrane disks modified by 6 mg of L 1 or 4 mg of L 2 was found to be 284.7 (±2.8) g of copper and 382.5 (±3.1) g of copper, respectively. The detection limits of the presented methods are 0.29 ng ml −1 for L 1 and 0.25 ng ml −1 for L 2. The enrichment factors are greater than 400 for both cases. These methods were successfully applied to the extraction, recovery and detection of copper in different water samples.
2010
A new chelating resin is prepared by coupling Amberlite XAD-4 with 1-amino-2-naphthole through an azo spacer. The resulting sorbent has been characterized by FT-IR, elemental analysis and thermogravimetric analysis (TGA) and studied for preconcentrating of Cu (II) using flame atomic absorption spectrometry (FAAS) for metal monitoring. The optimum pH value for sorption of the copper ions was 6.5. The resin was subjected to evaluation through batch binding of mentioned metal ion. Quantitative desorption occurs instantaneously with 0.5 M HNO3. The sorption capacity was found 4.8 mmol.g-1 of resin for Cu (II) in the aqueous solution. The chelating resin can be reused for 10 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 99% was obtained the metal ions with 0.5 M HNO3 as eluting agent. The method was applied for metal ions determination from industrial waste water sample.
DOAJ (DOAJ: Directory of Open Access Journals), 2013
A highly convenient, selective and sensitive procedure for pre-concentration, separation and determination of sub-ppm levels of Cu 2+ in aqueous samples based on modification of octadecyl silica bonded phase membrane (OSBPM) disks is described using benzildithiosemicarbazone (BDSC) as a powerful modifier. It was revealed that each loaded OSBPM disk with 6.0 mg of BDSC serves as excellent bead for trapping, enrichment and isolation of trace copper. The analyte was trapped during introduction the aqueous solutions through the surface of each modified membrane, quantitatively, while other interfering ions passed through the disk to drain. The adsorbed Cu 2+ ions were then stripped by appropriate eluting agents followed by monitoring of the eluates by FAAS. The effects of sample pH, amount of the modifier, stripping agent types and sample flowrates were also investigated. The described method permitted a pre-concentration factor of about 200. The detection limit of the procedure was predicted to be about 0.013 ng L-1. The method was successfully employed for recovery and quantification of trace copper in different water samples.
Journal of the Chinese Chemical Society, 2010
This report describes the capability of two facile, sensitive and concentrative methods for quantification of sub-ppm levels of copper in different solutions using octadecyl silica bonded phase membrane (OSPM) disks. The first standpoint is based on introduction a homogenized miscellaneous solution of copper-1-(2-pyridylazo)-2-naphtol (PAN) to the surface of an OSPM disk. The second perspective is the usual manner and is performed by impregnation or modification of the sorbent surface. All the affecting experimental variables such as pH, amount of modifier, eluent type, concentration of each metal and ligand, surfactant type, sample and eluent flow-rate, time and disk capacity are also tested. The results reveal that the first way is considerably more time consuming. However, the second method possesses high breakthrough volume (2000 mL) and lower detection limit (0.01 ng mL-1). Both the methods have been successfully applied for isolation and determination of trace copper in different aqueous and real samples.
Orbital: The Electronic Journal of Chemistry, 2018
A procedure for separation and preconcentration of trace amounts of Cu 2+ and Cd 2+ from aqueous media is proposed. The procedure is based on the adsorption of Cu 2+ and Cd 2+ ions on octadecyl bonded silica membrane disk modified with, Pyridine 2,6-diylbis{2,2'(azamethane-1-ylidene)4-bromophenol} (L) at pH = 8. The ligand has been synthesized by reaction of the 2,6-diamino pyridine and 5-bromo salicylaldehyde at ethanol under refluxing. The structure of the synthesized compound resulted from the Fourier-transform infrared spectroscopy (FTIR), Proton nuclear magnetic resonance (1 H NMR), Mass spectrometry (MS) and UV spectroscopy and elemental analysis data. The solid phase extraction experimental conditions were optimized by changing several parameters such as volume of eluting solvent, the effect of pH, limit of detection and maximum capacity of the disks for Cu 2+ and Cd 2+ recovery. The retained Cu 2+ and Cd 2+ ions were then stripped from the disk with a minimal amount of 0.7 mol.L-1 nitric acid and 1 mol.L-1 hydrochloric acid solution as eluent respectively, and determined by flame atomic absorption spectrometry. The limit of detection of the proposed method was 7.6 and 3.6 ng.mL-1 for copper and cadmium ions, respectively. The method was successfully applied to determination of copper and cadmium in natural biological samples and the method was quantitative.
Korean Journal of Chemical Engineering, 2011
A chelating resin is produced by coupling a dye calcein blue to Amberlite XAD-2 through an azo spacer. The resulting resin has been characterized by FT-IR, elemental analysis, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) studied for the preconcentration and determination of trace Cu(II) from solution samples. The optimum pH for adsorption of copper ions was 6. The sorption capacity of functionalized resin is 27 mg•g −1. The chelating resin can be reused for 10 cycles without any significant changes in sorption capacity. A recovery of 100% was obtained for Cu(II) when eluted with 0.5 M nitric acid. Scatchard analysis revealed that homogeneous binding sites were formed in the resin. The equilibrium adsorption data of Cu(II) on modified resin were analyzed by Langmuir, Freundlich and Temkin models. Based on equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined 0.036, 2.196 and 0.348 at pH 6 and 20 o C, respectively. The method was applied for Cu(II) assay in environmental samples.
Journal of AOAC INTERNATIONAL, 2008
A simple, selective, reliable, and sensitive method for the determination of trace amounts of Cu2+ ions in aqueous samples is proposed. The Cu2+ ions are adsorbed quantitatively during the passage of aqueous samples through an octadecyl (C18) silica membrane disk modified by a symmetrical tetradentate Schiff base ligand, N,N'-bis(4-phenylazo salicylaldimine) 3-chloro-1,2-phenylenediamine (H2L). The retained Cu2+ ions were then stripped from the disk by elution with the minimal amount of nitric acid solution and determined by flame atomic absorption spectrometry. Various parameters, such as the effect of pH, flow rate, type and amount of eluent, and the effects of various cationic interferences on the recovery of ions were studied. The proposed method permitted large enrichment factors (about 550 and higher). The limit of detection of the method was 1.5 102 g/L. The use of the same disk modified with 6 mg H2L for at least 30 times showed no change in the recovery of Cu2+ ions. Th...
In this work, a styrene-divinylbenzene based resin has been functionalized with 2-Hydroxy-3-methoxybenzaldehyde with the objective of employing it for the preconcentration of Zn(II), Cu(II), Ni(II), Cd(II), and Pb(II) contained in trace amount in various matrices. The optimum pH range for the maximum sorption of Zn(II), Cu(II), Ni(II), Cd(II), and Pb(II) was observed at pH 5.5-9.0, with the half-loading time, t 1/2 , ranging from 5 to 13.7 min. The sorption of these metal ions in presence of potentially interfering matrices (including naturally occurring chelating agents) was investigated. The synthesized resin was able to preconcentrate metal ions at concentration as low as 5.55-8.33 µg L-1 , thereby resulting in the preconcentration factor in range of 240-360. The results favour the applicability of this method for the simultaneous preconcentration and determination of all the metal ions constituting complex matrices. The method has been successfully applied to the determination of the heavy metals in natural waters as well as food samples.