Separation and Preconcentration of Cr(VI) as Ion Associate Using Solid Phase Extraction

2000 ◽  
Vol 65 (12) ◽  
pp. 1865-1874 ◽  
Author(s):  
Vítězslav Otruba ◽  
Jan Pivnička ◽  
Viktor Kanický
Keyword(s):  
Solid Phase ◽  
Modified Silica Gel ◽  
Limits Of Detection ◽  
Onium Salts ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Tetraphenylarsonium Chloride ◽  
Tenfold Excess ◽  
Ion Associate ◽  
Ph Range

A method of separation and preconcentration of Cr(VI) was developed based on sorption on modified silica gel (C18) of an ion associate of Cr(VI) anion with a quaternary base. The study was performed with the following quaternary onium salts: [1-(ethoxycarbonyl)- pentadecyl]trimethylammonium bromide, 1-hexadecylpyridinium chloride, benzyl(dodecyl)- dimethylammonium bromide, butyl(triphenyl)phosphonium bromide and tetraphenylarsonium chloride. Benzyl(dodecyl)dimethylammonium bromide was found the optimum ion-pairing reagent. Sample containing Cr(III) and Cr(VI) in the presence of 0.005 mol/l of benzyl(dodecyl)dimethylammonium bromide was pumped with a peristaltic pump through the column containing the sorbent. The optimum pH range 4-5 was maintained with 0.05 mol/l phosphate buffer. Elution was accomplished using 95 vol.% ethanol and the recovery of Cr(VI) was (96 ± 6)% in the concentration range 0.005-1 mg/l of Cr(VI); even in a tenfold excess of Cr(III) the recovery of Cr(VI) was 99.8% with the relative standard deviation of repeatability about 2.4% Cr in the eluate was determined by emission flame spectrometry (Cr I 425.435 nm) in an air-acetylene or N2O-acetylene flame with the limits of detection 10 or 2 ng/ml, respectively. Hence, with a typical preconcentration factor of 200, the limits of detection in natural aqueous samples were 50 and 10 pg/ml, respectively. Calibrations were linear at least up to 10 mg/l.

Green Dispersive Micro Solid-Phase Extraction using Multiwalled Carbon Nanotubes for Preconcentration and Determination of Cadmium and Lead in Food, Water, and Tobacco Samples

2020 ◽  
Vol 16 (4) ◽  
pp. 381-392
Author(s):  
Ayman A. Gouda ◽  
Ali H. Amin ◽  
Ibrahim S. Ali ◽  
Zakia Al Malah
Keyword(s):  
Carbon Nanotubes ◽  
Solid Phase Extraction ◽  
Multiwalled Carbon Nanotubes ◽  
Solid Phase ◽  
Certified Reference Materials ◽  
Phase Extraction ◽  
Multiwalled Carbon ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Separation And Preconcentration

Background: Cadmium (Cd2+) and lead (Pb2+) have acute and chronic effects on humans and other living organisms. In the present work, new, green and accurate dispersive micro solid-phase extraction (DμSPE) method for the separation and preconcentration of trace amounts of cadmium (Cd2+) and lead (Pb2+) ions in various food, water and tobacco samples collected from Saudi Arabia prior to its Flame Atomic Absorption Spectrometric (FAAS) determinations was developed. Methods: The proposed method was based on a combination of oxidized multiwalled carbon nanotubes (O-MWCNTs) with a new chelating agent 5-benzyl-4-[4-methoxybenzylideneamino)-4H- 1,2,4-triazole-3-thiol (BMBATT) to enrich and separate trace levels of Cd2+ and Pb2+. The effect of separation parameters was investigated. The validation of the proposed preconcentration procedure was performed using certified reference materials. Results: Analyte recovery values ranged from 95-102%, indicating that the method is highly accurate. Furthermore, precision was demonstrated by the relative standard deviation (RSD < 3.0%). The limits of detection were 0.08 and 0.1 μg L−1 for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 200. Conclusion: The proposed method was used for the estimation of Cd2+ and Pb2+ ion content in various real samples, and satisfactory results were obtained. The proposed method has high adsorption capacity, rapid adsorption equilibrium, extremely low LODs, high preconcentration factors and shortens the time of sample preparation in comparison to classical SPE.

scholarly journals The Solid Phase Extraction of Some Metal Ions Using Palladium Nanoparticles Attached to Silica Gel Chemically Bonded by Silica-Bonded N-Propylmorpholine as New Sorbent prior to Their Determination by Flame Atomic Absorption Spectroscopy

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
M. Ghaedi ◽  
M. Rezakhani ◽  
S. Khodadoust ◽  
K. Niknam ◽  
M. Soylak
Keyword(s):  
Electron Microscopy ◽  
Metal Ions ◽  
Silica Gel ◽  
Solid Phase ◽  
Food Samples ◽  
Natural Food ◽  
Modified Silica Gel ◽  
Flame Atomic Absorption ◽  
Relative Standard

In this research at first palladium nanoparticle attached to a new chemically bonded silica gel has been synthesized and has been characterized with different techniques such as X-ray diffraction (XRD), fourier transform infrared (FT-IR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Then, this new sorbent (chemically modified silica gel with N-propylmorpholine (PNP-SBNPM)) was efficiently used for preconcentration of some metal ions in various food samples. The influence of effective variables including mass of sorbent, flow rate, pH of sample solutions and condition of eluent such as volume, type and concentration on the recoveries of understudy metal ions were investigated. Following the optimization of variables, the interfering effects of some foreign ions on the preconcentration and determination of the investigated metal ions described. At optimum values of variables, all investigated metal ions were efficiently recovered with efficiency more than 95%, relative standard deviation (RSD) between 2.4 and 2.8, and detection limit in the range of 1.4–2.7 ng mL−1. The present method is simple and rapidly applicable for the determination of the understudied metal ions (ng mL−1) in different natural food samples.

scholarly journals Solid phase selective separation and green preconcentration of Cu, Zn, Pb and Cd in drinking water by using novel functionalized resin

2009 ◽  
Vol 7 (4) ◽  
pp. 945-954 ◽  
Author(s):  
Nagwa Burham ◽  
Sami Azeem ◽  
Mohamed El-Shahat
Keyword(s):  
Drinking Water ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Exchange Capacity ◽  
Coupling Reactions ◽  
Lead And Cadmium ◽  
Sample Flow Rate ◽  
Relative Standard ◽  
Copper Zinc ◽  
Ph Range

AbstractA new solid — phase extraction sorbent was developed based on stepwise anchoring of two ligand molecules for the determination of copper, zinc, lead and cadmium in drinking water by flame AAS. Amberlite XAD-2 functionalized with 4′-(2-hydroxyphenylazo)-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one (HPAPyr) was utilized for preconcentration/separation of these elements. The sorbent was prepared by two successive azo coupling reactions. First, 2-aminophenol was anchored to the amino groups in the resin resulted from nitration followed by reduction. Then, the resulted 2-aminophenol functionalized resin was further diazotized and coupled to the pyrazolone compound and the final product HPAPyr-XAD-2 was characterized by IR and elemental analysis. The optimum pH range for sorption, shaking time, exchange capacity, sample flow rate, preconcentration factor and interference from co-existing ions were investigated. All metal ions were quantitatively desorbed from the resin by 4.5 mol L−1 nitric acid solution. The sorbent provides limit of detection within the range 0.9–3.3 µg L−1 and concentration factor up to 250. The procedure was validated by analysis of certified material NIST-SRM 1577b. Application to drinking water showed satisfactory results with relative standard deviation RSD ≤ 8.5%.

Preparation of Adsorbents Based on Dendrimer Modified Silica Gel and its Adsorption Performances for Lead

2013 ◽  
Vol 800 ◽  
pp. 166-172
Author(s):  
Xiong Zhi Wu ◽  
Li Li ◽  
Fei Ping Li ◽  
Wen Ying Jin
Keyword(s):  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Silica Gel ◽  
Limit Of Detection ◽  
Modified Silica ◽  
Modified Silica Gel ◽  
Flame Atomic Absorption ◽  
Relative Standard ◽  
Separation And Preconcentration

A new sorbent (PAMAM4.0GASG) with gallic acid as functional group has been prepared based on G4.0 polyamidoamine dendrimer modified silica gel (PAMAM4.0SG) and characterized with FTIR. It was employed for selective separation, preconcentration and determination of lead in different samples by flame atomic absorption spectrometry (FAAS). Experimental conditions for effective separation and preconcentration of lead were optimized. The preconcentration factor reaches 200 for lead. The relative standard deviation (R.S.D.) under optimum conditions was 2.1% for 5.0 μg ml1 of Pb (II).The relative standard deviation (R.S.D.) was 2.1% for 5.0 μg ml1 of Pb (II). The limit of detection (LOD) of 0.081μg ml1 was achieved with a sample loading flow rate of 4.2 ml min1 and a 10 ml sample volume in the proposed method. The proposed column enrichment method was applied for the preconcentration/separation and determination of Pb (II) in tap water and river water samples successfully.

scholarly journals The Use of Silver Solid Amalgam Electrodes for Voltammetric and Amperometric Determination of Nitrated Polyaromatic Compounds Used as Markers of Incomplete Combustion

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Oksana Yosypchuk ◽  
Jindřich Karásek ◽  
Vlastimil Vyskočil ◽  
Jiří Barek ◽  
Karolina Pecková
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Solid Phase ◽  
Linear Calibration ◽  
Amperometric Determination ◽  
Limits Of Detection ◽  
Incomplete Combustion ◽  
Separation And Preconcentration ◽  
Polycyclic Aromatic

Genotoxic nitrated polycyclic aromatic hydrocarbons (NPAHs) are formed during incomplete combustion processes by reaction of polycyclic aromatic hydrocarbons (PAHs) with atmospheric nitrogen oxides. 1-Nitropyrene, 2-nitrofluorene, and 3-nitrofluoranthene as the dominating substances are used as markers of NPAHs formation by these processes. In the presented study, voltammetric properties and quantification of these compounds and of 5-nitroquinoline (as a representative of environmentally important genotoxic heterocyclic compounds) have been investigated using a mercury meniscus modified silver solid amalgam electrode (m-AgSAE), which represent a nontoxic alternative to traditional mercury electrodes. Linear calibration curves over three orders of magnitude and limits of determination mostly in the 10−7 mol L−1concentration range were obtained using direct current and differential pulse voltammetry. Further, satisfactory HPLC separation of studied analytes in fifteen minutes was achieved using 0.01 mol L−1phosphate buffer, pH 7.0 : methanol (15 : 85, v/v) mobile phase, and C18reversed stationary phase. Limits of detection of around 1 · 10−5 mol L−1were achieved using amperometric detection at m-AgSAE in wall-jet arrangement for all studied analytes. Practical applicability of this technique was demonstrated on the determination of 1-nitropyrene, 2-nitrofluorene, 3-nitrofluoranthene, and 5-nitroquinoline in drinking water after their preliminary separation and preconcentration using solid phase extraction with the limits of detection around 1 · 10−6 mol L−1.

Simultaneous Spectrophotometric Determination of Brilliant Blue and Tartrazine in Diverse Sample Matrices after Solid Phase Extraction

2020 ◽  
Vol 103 (6) ◽  
pp. 1478-1485
Author(s):  
Abdullah Taner Bişgin
Keyword(s):  
Spectrophotometric Determination ◽  
Solid Phase ◽  
Brilliant Blue ◽  
Liquid Samples ◽  
Quantitative Extraction ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Preconcentration Factor ◽  
Experienced Operator

Abstract Background Brilliant blue (BB) and tartrazine (TZ) are manufactured from petroleum and its products. These are the most popular consumed food dyes and are widely used in foodstuffs. Therefore, overuse of these dyes in foodstuffs and consumption of excessive amounts of these dyes can lead to health problems in humans. Objective The aim of this study was to develop a simple separation and preconcentration method for simultaneous spectrophotometric determination of BB and TZ dyes. Methods A column solid-phase separation extraction method combined with UV-Vis spectrophotometry was preferred and developed for single and simultaneous determination of BB and TZ dyes. Results The preconcentration factor was obtained as 80. Relative standard deviations were below than 4%. Detection limits of the method were determined as 0.29 and 1.21 µg/L for BB and TZ, respectively. Recovery values were obtained between 95–99% and 96–100% for BB and TZ, respectively. 10.9–235.7 µg/g and 1.7–8.0 µg/mL of BB contents of real samples were determined for solid and liquid samples, respectively. TZ concentrations of solid and liquid samples were ranged between 18.7–220.7 µg/g and 5.9–7.5 µg/mL, respectively. Conclusions Quantitative extraction results and satisfactory recovery values showed that method was successful and applicable for determination of BB and TZ concentrations in real pharmaceutical, industrial, and foodstuff samples. Highlights The method has exhibited a high preconcentration factor and effective separation against to matrix ions. The method did not need an experienced operator with high operation experience. Elution solvent can be chosen according to the availability of the chemicals in the laboratory and cheapness of the chemicals.

scholarly journals Solid-phase microextraction of benzophenones coupled with gas chromatography analysis

2016 ◽  
Vol 4 (2) ◽  
pp. 55-62
Author(s):  
Valentyna Levchyk ◽  
M. Zui
Keyword(s):  
Gas Chromatography ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Enrichment Factors ◽  
Chromatography Analysis ◽  
Fiber Coating ◽  
Flame Ionization ◽  
Gas Chromatography Analysis ◽  
Relative Standard ◽  
Ph Range

In this study, solid-phase microextraction method combines with gas chromatography-flame ionization detector. The proposed method is used for the preconcentration of some benzophenones. Influence of different factors on the efficiency of extraction is described in detail. The analytical procedure was optimized for fiber coating selection, extraction time, temperature, sample pH, ionic strength. For all benzophenones, the highest enrichment factors were achieved using carboxen/polydimethylsiloxane/divinylbenzene fibre immersed directly into the water samples, containing 100 mg/mL of sodium chloride, at room temperature. The optimum pH range is 5.0 – 7.0. The relative standard deviations (RSDs) were from 1.3 to 10.0 % (n = 3). The method was applied to the determination of benzophenone, benzophenone-3, 2-hydroxybenzophenone in the lake water and urine.

scholarly journals Using nanometer TiO2 modified with cetyl trimethyl ammonium bromide for separation and preconcentration of Parathion in water sample

2016 ◽  
Vol 17 (2) ◽  
pp. 362-371
Author(s):  
Haghighe Fathi ◽  
Robab Soltani-Jigheh ◽  
Saeed Hemmati
Keyword(s):  
Water Samples ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Solid Phase ◽  
Environmental Water ◽  
Sample Volume ◽  
Ammonium Bromide ◽  
Base Line ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Cetyl Trimethyl Ammonium

In this work, nanometer TiO2 modified by cetyl trimethyl ammonium bromide (CTAB) was used as adsorbent for solid-phase extraction (SPE) of Parathion in environmental water samples. Adsorbed Parathion was then desorbed with different eluents and determined by gas chromatography (GC)/flame ionization detection. Greater selectivity, resolution, and sensitivity have been seen by GC compared with other methods. Parameters that might influence the extraction efficiency, such as the eluent type and its volume, adsorbent amount, sample volume, sample pH and sample flow rate, were optimized. Under the optimized extraction conditions with toluene as the eluent, the experimental results showed the excellent linearity of Parathion (R2 &gt; 0.99) over the range of 0.01–0.8 μg/mL, and the relative standard deviation was 6.3% (n = 5). The detection limit of the proposed method could reach 0.024 ng/mL based on the ratio of chromatographic signal to base line noise (S/N = 3). Recovery of 93% was achieved with spiked water samples. The method was successfully applied to the analysis of surface water samples.

scholarly journals Magnetic Polydopamine Modified with Choline-Based Deep Eutectic Solvent for the Magnetic Solid-Phase Extraction of Sulfonylurea Herbicides in Water Samples

2020 ◽  
Vol 59 (1) ◽  
pp. 95-102
Author(s):  
Dan-Dan Wang ◽  
Zhi-Heng Lu ◽  
Xiao-yu Guan ◽  
Mei-Nan Ou Yang ◽  
Hao-Ming Guo ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Water Samples ◽  
Solid Phase ◽  
Magnetic Solid Phase Extraction ◽  
Infrared Spectrometry ◽  
Phase Extraction ◽  
Sulfonylurea Herbicides ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Magnetic Solid

Abstract A novel magnetic solid-phase extraction technique coupled to ultraperformance liquid chromatography has been developed for separation and preconcentration of four sulfonylurea herbicides (sulfosulfuron, bensulfuron-methyl, pyrazosulfuron-ethyl and halosulfuro-methyl) in aqueous samples. The key point of this method was the application of a novel magnetic nanomaterial that composed of a low eutectic solvent as a shell coated on the magnetic core modified by polydopamine. The extensive active sites outside the low eutectic solvent can effectively adsorb the target herbicide in the extraction process. The obtained magnetic adsorbent was characterized with fourier transform infrared spectrometry, scanning electron microscopy and vibrating sample magnetometer. The influence parameters relevant to this method were optimized. Under the optimum conditions, good linearities could be obtained within the range of 1.0–200 μg L−1 for all analytes, with correlation coefficients ≥0.9908. The limit of detections of the method was between 0.0074 and 0.0100 μg L−1 and the relative standard deviations were 1.1–3.6%. The enrichment factor is 66.6. In the final experiment, the proposed method was successfully applied to the analysis of sulfonylurea herbicides residue in environment and drinking-water samples, and the obtained recoveries were between 70.6% and 109.4%.

scholarly journals Development of ultrasound-assisted dispersive solid-phase microextraction based on mesoporous carbon coated with silica@iron oxide nanocomposite for preconcentration of Te and Tl in natural water systems

2020 ◽  
Vol 18 (1) ◽  
pp. 412-425
Author(s):  
Luthando Nyaba ◽  
Buyile Dubazana ◽  
Anele Mpupa ◽  
Philiswa N. Nomngongo
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Sol Gel ◽  
Emission Spectrometry ◽  
X Ray ◽  
Relative Standard ◽  
Separation And Preconcentration ◽  
Ultrasound Assisted

AbstractThe main objective of this study was to develop an ultrasound-assisted dispersive solid-phase microextraction (UADSPME) method for separation and preconcentration of tellurium (Te) and thallium (Tl) in environmental samples prior to inductively coupled plasma-optical emission spectrometry determination. The MPC@SiO2@Fe3O4 nanocomposite was used as a nanoadsorbent in the UADSPME method. The nanocomposite was prepared using a coprecipitation and sol–gel method, and it was characterized using scanning electron microscopy/energy-dispersive X-ray spectroscopy, transmission electron microscopy and X-ray powder diffraction techniques. The Box–Behnken design and response surface methodology were used for the optimization of experimental parameters (such as pH, extraction time and mass of adsorbent) affecting the preconcentration procedure. Under optimized conditions, the limits of detection were 0.05 and 0.02 µg L−1 and the limits of quantification were 0.17 and 0.07 µg L−1 for Te and Tl, respectively. The precision expressed as the relative standard deviation (%RSD) was 2.5% and 2.8% for Te and Tl, respectively. Finally, the developed method was applied for the analysis of Tl and Te in real samples.

Sign in / Sign up

Export Citation Format

Share Document