scholarly journals Solid phase extraction of zinc with octadecyl silica membrane disks modified by N,N’-disalicylidene-1,2-phenylendiamine and determination by flame atomic absorption spectrometry

2018 ◽  
Vol 33 (2) ◽  
pp. 61
Author(s):  
M. Shabany ◽  
Ali Mohammad Haji Shabani ◽  
Shayessteh Dadfarnia ◽  
Alireza Gorji ◽  
S. H. Ahmadi

A procedure for separation and preconcentration of trace amounts of Zn(II) from aqueous media is proposed. The procedure is based on the adsorption of Zn2+ on octadecyl bonded silica membrane disk modified with N,N’-disalicylidene-1,2-phenylendiamine at pH 7. The retained zinc ions were then stripped from the disk with a minimal amount of 1.5 mol L-1 hydrochloric acid solution as eluent, and determined by flame atomic absorption spectrometry. Maximum capacity of the membrane disk modified with 5 mg of the ligand was found to be 226 μg Zn2+. The relative standard deviation of zinc for ten replicate extraction of 10 μg zinc from 1000 mL samples was 1.2%. The limit of detection of the proposed method was 14 ng of Zn2+ per 1000 mL. The method was successfully applied to the determination of zinc in natural water samples and accuracy was examined by recovery experiments and independent analysis by graphite furnace atomic absorption spectrometry (GFAAS).

2008 ◽  
Vol 91 (4) ◽  
pp. 865-870 ◽  
Author(s):  
Tayebeh Shamspur ◽  
Ali Mostafavi ◽  
Iran Sheikhshoaie

Abstract 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. The accuracy of the method was confirmed by determination of Cu2+ ions in standard samples [National Institute of Environmental Studies (NIES) No. 2 and Nippon Keikinzoku Kogyo (NKK) No. 920]. The results demonstrated good agreement with certified values.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Güzin Alpdoğan ◽  
Nevim San ◽  
Şule Dinç Zor

A new procedure for separation and preconcentration of trace amounts of Cu(II), Ni(II), Fe(III), Zn(II), Cr(III), Cd(II), and Pb(II) in fish samples was proposed. The procedure is based on the adsorption of these metal ions on the column of Amberlite XAD-7 as congo red complexes prior to their determination by flame atomic absorption spectrometry (FAAS). Several factors that can affect the sorption and elution efficiency of the metal ions were investigated and optimized. The sorption was quantitative in the pH range of 6.0–9.0 for Cu(II) and Ni(II), 5.5–8.0 for Fe(III), 6.0–8.5 for Zn(II) and Cd(II), and 7.0–8.5 for Cr(III) and Pb(II). The optimum pH for simultaneous retention was 7.5. The sorption capacity of the resin was found to be 0.89, 0.72, 0.82, 0.61, 0.53, 0.84, and 0.78 mg/g for Cu(II), Ni(II), Fe(III), Zn(II), Cr(III), Cd(II), and Pb(II), respectively. The precision of the method was evaluated as the relative standard deviation obtained by analyzing a series of six replicates and below 6% for all seven elements. The validation of the method was performed by the analysis of certified reference materials. The proposed method was successfully applied to separation/preconcentration and determination of these metals in fish samples.


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.


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