Homa Shafieekhani; Ali Moadelli; Firoozeh Aminipour
Abstract
In this paper, magnetic nanoparticles functionalized by triazene ligand were prepared for extraction/preconcentration of trace amounts of mercury ions in water samples former on its determination with UV-Vis spectrophotometry. The modified magnetic nanoparticles were characterized by the various techniques ...
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In this paper, magnetic nanoparticles functionalized by triazene ligand were prepared for extraction/preconcentration of trace amounts of mercury ions in water samples former on its determination with UV-Vis spectrophotometry. The modified magnetic nanoparticles were characterized by the various techniques such as Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and X –Ray Diffractometry (XRD). In the separation process, aqueous solution of Hg2+ ion was mixed with Fe3O4 magnetite nanoparticles modified with (E)-1-(2-Ethoxyphenyl)-3-(4-nitrophenyl)triaze-1-ene (ENT), (MNPs@SiO2-ENT) and then external magnetic field was applied for isolation of magnetite nanoparticles containing mercury ions. Experimental conditions for effective adsorption including pH, ENT amount, Fe3O4 NPs amounts, and eluent type have been studied and established. Under the optimal extraction and preconcentration conditions, calibration curve was linear in the range of 4–80 µgL-1 with r2 = 0.9992 (n=20), the limit of detection (LOD) 1.05µg L-1 and enrichment factor was 38, respectively. This technique was successfully used for the determination of Hg (II) in aqueous samples.
Sayed Zia Mohammadi; Maryam Balengei; Alieyeh Pourhasanghani; Samieh Fozooni; Asghar Amiri
Volume 5, Issue 1 , March 2018, , Pages 1-8
Abstract
A preconcentration procedure, based on the coprecipitation of Mn2+, Co2+, Ni2+, Cd2+ and Cu2+ ions using a new organic coprecipitant, (2-(4-{[(4-{5-oxo-4-[1-(2-thienyl) methylidene]- 4,5-dihydro- 1,3- oxazole-2-yl} phenyl) imino] methyl} phenyl) methylidene ] amino} phenyl) -4-[ 1-phenyl methylidene] ...
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A preconcentration procedure, based on the coprecipitation of Mn2+, Co2+, Ni2+, Cd2+ and Cu2+ ions using a new organic coprecipitant, (2-(4-{[(4-{5-oxo-4-[1-(2-thienyl) methylidene]- 4,5-dihydro- 1,3- oxazole-2-yl} phenyl) imino] methyl} phenyl) methylidene ] amino} phenyl) -4-[ 1-phenyl methylidene] -1,3-oxazole-5(4H)-one (OTMDO) without adding any carrier element has been developed. The resultant concentrated elements were determined by using flame atomic absorption spectrometer. The influences of some analytical parameters including pH, amount of the coprecipitant, standing time, centrifugation rate and time, sample volume and diverse ions were investigated on the quantitative recoveries of analyte ions. Under the optimized experimental conditions, the calibration curves for the analyte ions were studied. The relative standard deviations for seven replicate determinations of a mixture of 0.1 mg mL−1 Mn2+, Co2+, Ni2+, Cd2+ and Cu2+ ions in the original solution were 2.5, 2.4, 2.2, 2.1 and 2.5%, respectively. The detection limits based on 3Sb/m for Mn2+, Co2+, Ni2+, Cd2+ and Cu2+ ions in the original solution were 1.2, 1.3, 1.2, 0.6 and 1.5 ng mL−1, respectively. The proposed method has been applied for determination of trace amounts of the analyte ions in the standard, water samples; brewed tea; tobacco samples and satisfactory results were obtained.
Mohammad Reza Rezaei Kahkha; Massoud Kaykhaii; Mahdi Shafee-Afarani; Batool Rezaei Kahkha
Volume 4, Issue 2 , September 2017, , Pages 10-16
Abstract
In this work, a microextraction technique based on pipette tip solid-phase extraction was used for preconcentration and determination of diazinon. Carbon nanotube functionalized by zinc sulfide and ethylene glycol was used as sorbent. Determination of diazinon was performed using high performance liquid ...
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In this work, a microextraction technique based on pipette tip solid-phase extraction was used for preconcentration and determination of diazinon. Carbon nanotube functionalized by zinc sulfide and ethylene glycol was used as sorbent. Determination of diazinon was performed using high performance liquid chromatography and UV detection. Important parameters that influence the extraction efficiency (i.e. pH, amount of adsorbent, extraction time, salt addition, volumes of sample and eluting solvent and number of aspirating/dispensing cycles for both solvent and sample) were investigated and optimized. Results were showed that method was validated over the range of 0.50 - 100.0 µg L-1. Repeatability was satisfactory, bellow 3.78% for 5 replicate measurements of 20 µg L-1 of diazinon. The limit of detection of this method is 0.03 µg L-1 with an enrichment factor of 100 and short extraction time of 8.5 min, which confirmed suggested method is a reliable and accurate for extraction and preconcentration of diazinon.
Narges Vaezi; Nasser Dalali; Mehdi Hosseini
Volume 4, Issue 1 , March 2017, , Pages 59-66
Abstract
A simple, novel, accurate and selective method for the determination of trace amounts of Cu2+ ions in water and soil samples is proposed. The method is based on the separation and preconcentration of Cu2+ on a nano-SiO2 modified by a cetyltrimethylammonium bromide as surfactant and indane-1,2,3-trione-1,2-dioxime ...
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A simple, novel, accurate and selective method for the determination of trace amounts of Cu2+ ions in water and soil samples is proposed. The method is based on the separation and preconcentration of Cu2+ on a nano-SiO2 modified by a cetyltrimethylammonium bromide as surfactant and indane-1,2,3-trione-1,2-dioxime as complexing agent. The retained copper on the nano-sorbent was eluted with 1.5 mL of 1.0 mol L-1 HNO3 and measured by flame atomic absorption spectrometry. The synthesis of this nano-sorbent is also described and certified by FTIR, XRD and TEM techniques. Furthermore, several effective analytical parameters were evaluated and optimized. Under the best optimum conditions maximum absorption capacity, enrichment factor and limit of detection were 7.04 mg g-1, 333.3 and 4.4 µg L-1, respectively. The relative standard deviation of the preconcentration method was 0.28% (n=7) and calibration curve gave good level of linearity with correlation coefficient value 0.997. Finally, the feasibility and performance of the method was evaluated by determination of copper (II) ions in several water and soil samples with satisfied results.
Sandeep Jaggi; Usha Gupta
Volume 1, Issue 2 , September 2014, , Pages 97-105
Abstract
A simple and sensitive method has been developed for the preconcentration and determination of trace level of Co(II) using UV-Vis spectrophotometry. β-Cyclodextrin polymer modified with 1-(2-pyridylazo)-2-naphthol (PAN) is used for the preconcentration of Co(II) from samples at pH 8.5. The polymer ...
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A simple and sensitive method has been developed for the preconcentration and determination of trace level of Co(II) using UV-Vis spectrophotometry. β-Cyclodextrin polymer modified with 1-(2-pyridylazo)-2-naphthol (PAN) is used for the preconcentration of Co(II) from samples at pH 8.5. The polymer is synthesized and characterized using elemental analysis, FT-IR and SEM analysis. The factors affecting the recovery of Co(II) such as pH, adsorbent dose, contact time, sample volume, eluent concentration and volume are also optimized in order to achieve higher sensitivity. The recoveries of Co(II) are found to be 95% and the relative standard deviation found by analyzing 3 replicates is ≤2.9. The preconcentration factor is found to be 100. The limit of detection (LOD) determined as (3σ) is found to be 4.2 ng/ml and limit of quantification (LOQ) determined as (10σ) is found to be 14 ng/ml. The recoveries achieved by addition of Co(II) at known concentrations to samples and analysis results show that the described method has a good accuracy. The proposed method is applied to water, vegetable and alloy samples successfully.
Mohammad Reza Jamali; Aysanam Kazemi
Volume 1, Issue 1 , March 2014, , Pages 36-43
Abstract
A simple, selective and efficient solid phase extraction method based on the use of γ-alumina nanoparticles coated with sodium dodecyl sulfate (SDS) and modified with 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol (5-Br-PADAP) as a new adsorbent was developed for ...
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A simple, selective and efficient solid phase extraction method based on the use of γ-alumina nanoparticles coated with sodium dodecyl sulfate (SDS) and modified with 2-(5-Bromo-2-pyridylazo)-5-(diethylamino) phenol (5-Br-PADAP) as a new adsorbent was developed for the separation and preconcentration of trace amounts of manganese (II) prior to determination by flame atomic absorption spectrometry. Analytical influencing parameters including pH value, amount of modified sorbent, equilibrium time, volume and concentration of eluent were examined. Under the optimum conditions, adsorption capacity of nano- Al2O3-SDS-5-Br-PADAP, enrichment factor and limit of detection for manganese (II) was 18.5 mg g -1, 25 and 0.9 µg L -1, respectively. The procedure was successfully applied to the determination of manganese (II) in water and milk samples.
Maryam Ghanbarian; Farzad Etemadi; Ali Mostafavi; Moslem Afzali
Volume 1, Issue 1 , March 2014, , Pages 53-57
Abstract
In this work, a selective method for separation and preconcentration of nickel ions at trace level on modified multiwalled carbon nanotubes columns and determination by flame atomic absorption spectrometry (FAAS) has been developed. Multiwalled carbon nanotubes were oxidized with concentrated HNO3 and ...
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In this work, a selective method for separation and preconcentration of nickel ions at trace level on modified multiwalled carbon nanotubes columns and determination by flame atomic absorption spectrometry (FAAS) has been developed. Multiwalled carbon nanotubes were oxidized with concentrated HNO3 and then modified with loading 1-(2-pyridylazo)-2-naphtol. The sorption of Ni(II) ions was quantitative in the pH =9. Elution of the adsorbed nickel was carried out with 5.0 mL of 0.1 mol L−1 HNO3. The amount of eluted nickel was measured using flame atomic absorption spectrometry. Factors influencing sorption and desorption of Ni(II) ions were investigated, including the sample pH, flow rates of sample and eluent solution, eluent type, breakthrough volume and interference ions. The relative standard deviation of the method was ±0.57% (n=8) and the limit of detection was 2.04 g mL−1 (3σb/m, n=8). The method was applied to the determination of Ni(II) in water samples and standard alloy (NKK. NO. 920, Aluminum Alloy).
