Solid phase extraction of trace amounts of silver (I) using dithizone-immobilized alumina-coated magnetite nanoparticles prior to determination by flame atomic absorption spectrometry

A new, simple, fast and reliable solid-phase extraction (SPE) method has been developed to separation/preconcentration of trace amounts of silver ion from environmental water samples using dithizone/sodium dodecyl sulfate immobilized on alumina-coated magnetite nanoparticles (DTZ/SDS-ACMNPs) and its determination by flame atomic absorption spectrometry. The coating of alumina on Fe₃O₄ NPs not only avoids the dissolving of Fe₃O₄ NPs in acidic solution, but also extends their application without sacrificing their unique magnetization characteristics. This method avoided the time-consuming column-passing process of loading large volume samples in traditional SPE through the rapid isolation of DTZ/SDS-ACMNPs with an adscititious magnet. Optimal experimental conditions including amount of DTZ/SDS, pH value, standing time, sample volume, type, volume and concentration of eluent and co-existing ions have been studied and established. Under the optimal experimental conditions, the detection limit for Ag(I) with enrichment factors of 100 was found to be 0.52?ng?mL^?1 and its relative standard deviations (RSD) was 3.4% (n?=?10, C?=?5.0?µg?mL^?1). The linear range of calibration curve for Ag(I) was 2–5000?ng?mL^?1 with a correlation coefficient of 0.9991. The proposed method was successfully applied to the determination of target analyte in different water and wastewater samples. The validity of the method has been checked by applying it to study the recovery of silver ion in spiked water and wastewater samples.     

Solid phase extraction of lead (II), copper (II), cadmium (II) and nickel (II) using gallic acid-modified silica gel prior to determination by flame atomic absorption spectrometry

The immobilization of gallic acid on the surface of amino group-containing silica gel phases for the formation of a newly chelating matrix (GASG) is described. The newly synthesized extractant, characterized by the diffuse reflectance infrared Fourier transformation spectroscopy and elemental analysis, was used to preconcentrate Pb(II), Cu(II), Cd(II) and Ni(II). The pH ranges for quantitative sorption and the concentrations of HCl for eluting Pb(II), Cd(II), Cu(II) and Ni(II) were opimized, respectively. The sorption capacity of the matrix has been found to be 12.63, 6.09, 15.38, 4.62mg/g for Pb(II), Cd(II), Cu(II) and Ni(II), respectively, with the preconcentration factor of approximately 200 ( approximately 100 for Cd(II)). The effects of flow rates, the eluants, the electrolytes and cations on the metal ions extraction, as well as the chelating matrix stability and reusability, were also studied. The extraction behavior of the matrix was conformed with Langmuir's equation. The present preconcentration and determination method was successfully applied to the analysis of synthetic metal mixture solution and river water samples. The 3sigma detection limit and 10sigma quantification limit for Pb(II), Cu(II), Cd(II) and Ni(II) were found to be 0.58, 0.86, 0.65, 0.92microg/L and 1.08, 1.23, 0.87, 1.26microg/L, respectively.     

Solid phase extraction of trace cadmium and lead in food samples using modified peanut shell prior to determination by flame atomic absorption spectrometry

Microchimica Acta - Peanut shell was chemically modified with phosphoric acid and used as a solid phase extraction material for the determination of trace amounts of Pb2+ and Cd2+ in food samples...     

Functionalized HMS mesoporous silica as solid phase extractant for Pb(II) prior to its determination by flame atomic absorption spectrometry

In this work, a mesoporous silica has been chemically modified with 5-mercapto-1-methyl-1-H-tetrazol using the homogeneous route (MTTZ-HMS). This synthetic route involved the reaction of 5-mercapto-1-methyl-1-H-tetrazol with 3-chloropropyltriethoxysilane, prior to immobilization on the support. The resulting material has been characterized and employed as solid phase extractant for Pb(II). The effect of several variables (stirring time, pH, temperature, metal concentration, presence of other metals) has been studied using batch and column techniques. In batch experiments, 15 min stirring time, 55 degrees C and pH 8 were the optimal conditions for Pb(II) adsorption. In column experiments, sorption was quantitative for 1000 mL of 2.41 x 10(-4 )mM of Pb(II) solution and adsorbed ions were eluted out by 5 mL of 1 M HCl (preconcentration factor of 200). Spiked tap water was used for the preconcentration and determination of Pb(II) by flame atomic absorption spectrometry, and a 100% recovery was obtained. The LOD and LOQ values of the proposed method were found to be 3.52 x 10(-3) and 4.20 x 10(-3 )mM, respectively. The RSD for three preconcentration experiments was found to be 相似文献   

Simultaneous separation and extraction of Ag(I), Pb(II) and Pd(II) ions by solid phase method and determination of these ions by flame atomic absorption spectrometry

A simultaneous preconcentration and separation method for determination of trace amount of dissolved Ag⁺, Pb²⁺ and Pd²⁺ ions by modified octadecyl silica membrane disks with DBzDA18C6 was developed. The adsorbed metal complexes were eluted from disk with 10?mL of 4?M KCl and determined by flame atomic absorption spectroscopy. Several parameters such as anion effect, pH of sample solution, type of eluent, amount of ligand, sample and elution flow rate were evaluated. The effect of diverse ions on preconcentration was also investigated. A precocentration factor of 110 can easily be achieved depending on the volume of the sample. For 100?mL of the solution the linear dynamic rang were found to be 30–1000, 140–6000, 60–900?μg?l^?1 for Ag⁺, Pb²⁺ and Pd²⁺, respectively. Based on three standard deviation of the blank the detection limit was obtained as 1.8, 8.0 and 4.2?μg?L^?1 for Ag⁺, Pb²⁺, Pd²⁺, respectively. The formation constants of Ag⁺ and Pb²⁺ ions with DBzDA18C6 at 25?°C were determined from the molar conductance–mole ratio data. This method was applied for the determination of Ag⁺, Pb²⁺ and Pd²⁺ in environmental water, tea and soil samples.     

Selective back-extraction and preconcentration of zinc(II) from metal-1,3,5-triketone extracts prior to its determination by flame atomic absorption spectrometry

A simple back-extraction method was developed for the separation and preconcentration of trace levels of zinc from different matrices. Ethyl-2-(4-methoxybenzoyl)-3-(4-methoxyphenyl)-3-oxopropanoylcarbamate (EMPC) was used as a new complexing agent for the extraction of zinc(II) from the aqueous sample phase to the methyl isobutyl ketone (MIBK) phase as Zn(EMPC)₂ complexes. The Zn(II) can be selectively stripped with 1?mL of 0.5?mol?L^?1 HCl from Mⁿ⁺(EMPC)_n complexes [Ag(I), Al(III), Cd(II), Cr(III), Cu(II), Fe(II), Fe(III), Mn(II), Ni(II), Pb(II) and Pd(II)] which dissolved in MIBK phase. Some experimental parameters, which are important for the whole extraction process, including pH, sample volume, shaking time, amount of the EMPC reagent, amount of MIBK, ionic strength, and type of back-extractant were investigated. The recovery for Zn(II) was greater than 95%. The detection limit of the method was found to be 0.2?µg?L ^{? 1} and the relative standard deviation as 6.4%. The concentrations of Zn(II) in the certified reference materials (LGC6019 river water and NIST-1547 peach leaves) by the presented method were in good agreement with the certified values. The proposed method was succesfully applied to the determination of zinc in some natural waters, rice, hair, soil, and tea samples.     

双硫腙螯合型树脂同时分离富集-火焰原子吸收光谱法测定痕量铅和镉

以大孔聚苯乙烯树脂为母体,通过-N=N-,与双硫腙键合,合成了双硫腙螯合型树脂,并将其应用于痕量铅和镉的同时分离富集,实验了酸度、流速、共存离子干扰等因素对双硫腙螯合型树脂吸附和洗脱Pb和Cd的影响,建立了双硫腙螯合型树脂同时分离富集-火焰原子吸收光度法测定食品及环境样品中痕量Pb和Cd的方法.对Pb和Cd,方法的检出限分别为0.015和0.0013μg/mL,相对标准偏差(RSD)均优于3.0%.     

Aluminium determination in environmental samples by graphite furnace atomic absorption spectrometry after solid phase extraction on Amberlite XAD-1180/pyrocatechol violet chelating resin

A chelating resin, pyrocatechol violet (PV) immobilised on an Amberlite XAD-1180 support, was prepared and its use for the atomic absorption spectrometric determination of aluminium was investigated. The XAD-1180-PV resin was characterised by infrared spectrometry and thermal gravimetric analysis. The optimum pH value for quantitative sorption is 8-9, and desorption can be achieved by using 5.0-10.0 ml of 2 M HCl. The effects of diverse ions on the sorption and recovery of aluminium have been studied. The capacity of sorbent was 6.45±0.59 mg g⁻¹ Al XAD-1180-PV. Recoveries for aluminium from water samples were in the range 95-105%. The accuracy of procedure was confirmed by aluminium determination in certified reference materials. The method developed was applied with varying results to the analysis of natural water, haemodialysis fluids and microwave digested red wine samples from Tokat City.     

Solid phase extraction of copper (II) by sorption on octadecyl silica membrane disk modified with a new Schiff base and determination with atomic absorption spectrometry

A simple, selective and reliable method for rapid extraction and determination of trace amounts of Cu (II) ions from aqueous samples using octadecyl-bonded silica membrane disks modified with bis-(3-methoxy salicylaldehyde)-1,6-diaminohexane and flame atomic absorption spectrometry (FAAS) is presented. Extraction efficiency, the influence of pH, flow rates, amount of ligand, and type and least amount of eluant were investigated. The linear dynamic range of the proposed method for Cu (II) ions was found in a wide concentration range of 1.0 (± 0.2)–150 (± 2) μg l^− 1. The detection limit and preconcentration factor of this method were found 30.0 (± 0.7) ng l^− 1 and 100 respectively. The reproducibility of the procedure is at the most 2.0%. The effects of various cationic interferences on the percent recovery of copper ion were studied. The method was used to the recovery of copper ion from different synthetic, alloys and biological samples.     

Solid phase extraction and determination of ultra trace amounts of copper(II) using octadecyl silica membrane disks modified by 11-hydroxynaphthacene-5,12-quinone and flame atomic absorption spectrometry

A simple and selective method for rapid extraction and determination of trace amounts of copper(II) ions using octadecyl-bonded silica membrane disks modified with 11-hydroxynaphthacene-5,12-quinone and flame atomic absorption spectrometry is presented. Extraction efficiency and the influence of pH, flow rates, amount of ligand and type and least amount of stripping acid were evaluated. Maximum capacity of the membrane disks modified by 5 mg of the ligand was found to be 360 mug of Cu(2+) ion. The break through volume is larger than 2000 ml. The limit of detection of the proposed method is 0.2 ng ml(-1). The effects of various cationic interferences on the percent recovery of copper in binary mixtures were studied. The method was applied to the recovery of Cu(2+) ions from four different water samples and a synthetic sample.     

Solid phase extraction of Pb(II) and Cd(II) as 2,9 dimethyl-4,7-diphenyl-1,10-phenanthroline chelates on activated carbon cloth in environmental samples and their determination by flame atomic absorption spectrometry

A solid-phase extraction procedure for Pb(II) and Cd(II) as 2,9 dimethyl-4,7-diphenyl-1,10-phenanthroline complexes on activated carbon cloth (ACC) has been established. In the determination step, flame atomic absorption spectrometry (FAAS) was used. The optimum conditions for pH, type and volume of eluent, volume of sample solution, flow rates of eluent, sample solution and matrix effect were determined. For quantitative recovery of the analyte ions, refereed optimum values are as follows: amount of ACC, 0.4 g; pH, 6.0 and eluent, 10 mL 3 M HNO₃. To test the accuracy of the method, a certified reference material (CRM) analysis and add-recovery methods were performed. The developed method was applied for the determination of the analyte elements in water and vegetable samples.     

Determination of Zn(II) in alcohol fuel by flame atomic absorption spectrometry after on-line preconcentration using a solid phase extraction system

The method for the determination of zinc in alcohol fuel by flame atomic absorption spectrometry using a solid phase extraction system containing Moringa oleifera seeds as biosorbent material is described. The multivariate optimization of hydrodynamic variables was performed using a full factorial design (2⁴) including the following factors: sorbent mass, preconcentration time, volume of eluent, sample flow rate, sample pH and eluent concentration. It was verified that the aforementioned factors as well as their conditions were statistically significant at the 95% confidence level. With the optimized conditions, the preconcentration factor and the limit of detection were estimated as 23 and 0.9 μg/L, respectively. The analytical curve was linear from 0 to up to 100 μg/L, with a correlation coefficient of 0.999. The developed method was successfully applied to alcohol fuel, and accuracy was assessed through recovery tests with results ranging from 96 to 100%.     

Speciation of iron (II) and (III) by using solvent extraction and flame atomic absorption spectrometry

A method for speciation, preconcentration and separation of Fe²⁺ and Fe³⁺ in different matrices was developed using solvent extraction and flame atomic absorption spectrometry. PAN as complexing reagent for Fe²⁺ and chloroform as organic solvent were used. The complex of Fe²⁺-PAN was extracted into chloroform phase in the pH range of 0.75-4.0 and Fe³⁺ remains in water phase in the pH range 0.75-1.25. The optimum conditions for maximum recovery of Fe²⁺ and minimum recovery of Fe³⁺ were determined as pH = 1, the stirring time of 20 min, the PAN amount of 0.5 mg and chloroform volume of 8 mL. The developed method was applied to the determination of Fe²⁺ and Fe³⁺ in tea infusion, fruit juice, cola and pekmez. It is seen that there is high bioavailable iron (Fe²⁺) in pekmez. The developed method is sensitive, simple and need the shorter time in comparison with other similar studies.     

The determination of lead in tapwater by resin pre-concentration followed by flame atomic absorption spectrometry

The preparation and use of a polystyrene-supported poly(maleic anhydride) resin for the preconcentration of lead from tapwater samples is described. After elution with dilute nitric acid, lead is determined by flame atomic absorption spectrometry down to levels well below the 50 ng cm^-3 E.E.C. limit.     

A new chelating resin for preconcentration and determination of Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II) by flame atomic absorption spectrometry

A new polychelatogen, AXAD-16-1,2-diphenylethanolamine, was developed by chemically modifying Amberlite XAD-16 with 1,2-diphenylethanolamine to produce an effective metal-chelating functionality for the preconcentration of Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II) and their determination by flame atomic absorption spectrometry. Various physiochemical parameters that influence the quantitative preconcentration and recovery of metal were optimized by both static and dynamic techniques. The resin showed superior extraction efficiency with high-metal loading capacity values of 0.73, 0.80, 0.77, 0.87, 0.74, and 0.81 mmol/g for Mn(II), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II), respectively. The system also showed rapid metal-ion extraction and stripping, with complete saturation in the sorbent phase within 15 min for all the metal ions. The optimum condition for effective metal-ion extraction was found to be a neutral pH, which is a great advantage in the preconcentration of trace metal ions from natural water samples without any chemical pretreatment of the sample. The resin also demonstrated exclusive ion selectivity toward targeted metal ions by showing greater resistivity to various complexing species and more common metal ions during analyte concentration, which ultimately led to high preconcentration factors of 700 for Cu(II); 600 for Mn(II), Ni(II), and Zn(II); and 500 for Cd(II) and Pb(II), arising from a larger sample breakthrough volume. The lower limits of metal-ion detection were 7 ng/mL for Mn(II) and Ni(II); 5 ng/mL for Cu(II), Zn(II), and Cd(II), and 10 ng/mL for Pb(II). The developed resin was successful in preconcentrating metal ions from synthetic and real water samples, multivitamin-multimineral tablets, and curry leaves (Murraya koenigii) with relative standard deviations of < or = 3.0% for all analytical measurements, which demonstrated its practical utility.     

Simultaneous determination of chromium(VI) and chromium(III) by flame atomic absorption spectrometry with a chelating ion-exchange flow injection system

Summary Simultaneous Determination of Chromium(VI) and Chromium(III) by Flame Atomic Absorption Spectrometry with a Chelating Ion-Exchange Flow Injection System A simple method is described for the simultaneous determination of chromium(VI) and chromium(III) in a flow injection system comprising chelating ion-exchange and flame atomic absorption spectrometry. Sampling rates for 2001 and 1 ml sample volumes were 120 and 60 h^–1 (240 and 120 speciations per hour), respectively. Typical relative standard deviations were 0.52% for Cr(VI) (0.50g ml^–1 and 0.67% for Cr(III) (0.10,g ml^–1) and the corresponding limits of detection were 85 ng ml^–1, and 16 ng ml^–1, respectively.On leave from University of Belgrade.     

On-line preconcentration of palladium(II) using a microcolumn packed with a chelating resin, and its subsequent determination by graphite furnace atomic absorption spectrometry

Palladium(II) is preconcentrated on a chelating resin microcolumn [1,5-Bis(2-pyridyl)-3-sulphophenyl methylene thiocarbonohydrazide immobilized on an anion-exchange resin (Dowex 1 X8-200)] placed in the autosampler arm, followed by the elution of the Pd-chelate with nitric acid and subsequent determination of Pd from the eluate by graphite furnace atomic absorption spectrometry. The method was applied to the recovery of Pd(II) ions from different samples.     

Coprecipitation of lead and cadmium using copper(II) mercaptobenzothiazole prior to flame atomic absorption spectrometric determination

A coprecipitation method using a combination of 2-mercaptobenzothiazole (MBT) as a chelating reagent and copper as the coprecipitate carrier is described for the determination of trace lead and cadmium by flame atomic absorption spectrometry. The coprecipitation conditions, such as the effect of pH, the amount of carrier element and reagent, standing time, sample volume and matrix effects were examined in detail. It was found that lead and cadmium are coprecipitated quantitatively (≥95%) with Cu(II)-MBT at pH 9 and that the relative standard deviations (n = 7) were ≤1.6%. When using the enrichment factors of 150-fold for lead and cadmium, the detection limits (3s/b) obtained are 1.08 for lead and 0.04 μg L⁻¹ for cadmium. The method was validated with spiked sea water, stream water, well water, and vegetable samples.     

流动注射在线三正辛胺萃淋树脂分离富集火焰原子吸收法测定银

使用填充三正辛胺（TOA）萃淋树脂的微型柱，采用流动注射在线分离富集与火焰子吸收法联用技术，对微量银的测定进行了研究。在1．0mol/L HCl介质中样品流速为8．1mL/min，采样60s，以0．25mol/L HCl-0.5mol/L硫脲洗脱。在30样／h的分析速度下，富集倍率为26倍，富集效率为26／min，消耗指数为0．31mL。线性范围为0－1000μg/L，检出限为1．2μg/L。银含量为50μg／L时，连续11次测定的相对标准偏差为1．4％。对铅锌冶炼矿渣样液进行加标回收率试验，回收率为91．1％－100．6％，并应用于测定光谱纯氧化镁中的微量银。