Ehsan Zolfonoun; Seyed Reza Yousefi
Abstract
A ligandless on-line solid phase extraction method was developed for the preconcentration of lead prior to quantitation by inductively coupled plasma-optical emission spectrometry. In this method, the sample solution was passed through a syringe membrane filter coated with graphitic carbon nitride and ...
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A ligandless on-line solid phase extraction method was developed for the preconcentration of lead prior to quantitation by inductively coupled plasma-optical emission spectrometry. In this method, the sample solution was passed through a syringe membrane filter coated with graphitic carbon nitride and Pb(II) ions were directly adsorbed on the surface of g-C3N4 particles. The adsorbed Pb(II) ions were subsequently eluted from the membrane and transferred directly into the ICP-OES nebulizer with nitric acid solution. Under the optimized conditions and preconcentration of 25 mL of sample, the enhancement factor of 110 and the detection limit of 0.12 μg L-1 were obtained. The proposed procedure was applied for the preconcentration and determination of lead in environmental water samples.
Mohammad Vahidifar; Zarrin Eshaghi; Ramin Rezaee
Abstract
In this paper, a new rapid and sensitive method based on sodium dodecyl sulfate modified Fe3O4@α–Linolenic acid nanocomposite combined with high-performance liquid chromatography-photo diode array detection (HPLC–PDA) has been proposed for the extraction and determination of tramadol ...
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In this paper, a new rapid and sensitive method based on sodium dodecyl sulfate modified Fe3O4@α–Linolenic acid nanocomposite combined with high-performance liquid chromatography-photo diode array detection (HPLC–PDA) has been proposed for the extraction and determination of tramadol (TRA) in water samples. The Fe3O4@α–Linolenic acid NPs were synthesized and then characterized by Fourier transform-infrared spectroscopy (FT−IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The main factors influencing extraction and desorption efficiency were optimized. Under optimum conditions, the method was successfully applied to the determination of TRA in the environmental samples and good linearity in the range of 0.1–500ng.mL-1(𝑅2> 0.99) obtained. The detection limit (LOD) and relative standard deviation (RSD) were0.074ng.mL-1 and 2.89 %( n=5) respectively. Finally, the proposed method was successfully applied with the relative recoveries percentages from 94–103.97% for the extraction and determination of tramadol in aqueous samples.
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.
Milan Modi; Punit Parejiya; Nikunj Patel; Rakesh Sutariya
Volume 4, Issue 2 , September 2017, , Pages 33-41
Abstract
A rapid, selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay has been proposed for the determination of Clavulanic acid (CA) in human plasma using Diclofenac sodium as internal standard (IS). The analyte and IS were extracted from human plasma via ...
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A rapid, selective and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) assay has been proposed for the determination of Clavulanic acid (CA) in human plasma using Diclofenac sodium as internal standard (IS). The analyte and IS were extracted from human plasma via solid phase extraction and the chromatographic separation was achieved on Inertsil ODS-3, 50 x 4.6 mm, 5µ column under isocratic conditions. Detection of CA and IS was done by tandem mass spectrometry, operating in positive ionization and multiple reaction monitoring (MRM) acquisition mode. The protonated precursor to product ion transitions monitored for CA and IS were m/z 365.2→240.2 and 409.2→228.2, respectively. The method was fully validated as per the US FDA guidelines. The linear dynamic range of CA was 7.564 - 897.893 ng/mL. The intra-batch and inter-batch precision (%CV) was ≤ 14.1% while the mean extraction recovery was 84.48 % across quality control levels. It was successfully applied to a bioequivalence study of Cefdinir/CA (125 mg/62.5 mg) suspension formulation in 32 healthy Indian male subjects under fasting condition.
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 Ali Karimi; Abdolhamid Hatefi-Mehrjardi; Alireza Mohadesi; Sayed Zia Mohammadi; Mehdi Taghdiri; Javad Yarahmadi; Havva Mahmoodian; Shahla Nezhad Khorasani
Volume 1, Issue 1 , March 2014, , Pages 7-11
Abstract
In this work, a new, simple and fast method for the solid phase extraction-spectrophotometric determination of phosphate using cetyltrimethyl ammonium bromide immobilized on alumina-coated magnetite nanoparticles (CTAB@ACMNPs) has been developed. The determination of phosphate is based on the molybdenum ...
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In this work, a new, simple and fast method for the solid phase extraction-spectrophotometric determination of phosphate using cetyltrimethyl ammonium bromide immobilized on alumina-coated magnetite nanoparticles (CTAB@ACMNPs) has been developed. The determination of phosphate is based on the molybdenum blue method which was monitored at λmax of 810 nm. MNPs and ACMNPs characterized by SEM, VSM, and XRD spectroscopy. This method avoided the time-consuming column-passing process of loading large volume samples in traditional SPE through the rapid isolation of CTAB@ACMNPs with an adscititious magnet. Under the optimal experimental conditions, the preconcentration factor (PF), detection limit (DL), linear range (LR) and relative standard deviation (RSD) of phosphate were 80 (for 400 mL of sample solution), 0.038 µg mL−1, 0.8-10.0 µg mL−1 and 2.5 % (for 5.0 µg mL-1, n=7), respectively. The proposed method was successfully applied to the separation/preconcentration and determination of phosphate in different water samples and suitable recoveries were obtained.
