Maryam Omidvar Motlagh; Zarrin Eshaghi; Hasan Ali Hosseini
Abstract
Contamination of water sources with chromium has become a pervasive global problem due to its wide use in industry. In this research, low-cost commercial sodium bentonite and synthesized nano bentonite were used to remove chromium ions from aqueous solutions along with electro thermal atomic absorption ...
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Contamination of water sources with chromium has become a pervasive global problem due to its wide use in industry. In this research, low-cost commercial sodium bentonite and synthesized nano bentonite were used to remove chromium ions from aqueous solutions along with electro thermal atomic absorption spectroscopy (ETAAS) and Ultraviolet-Visible Spectrophotometry (UV-Vis) were used. The morphology of the bentonite samples was studied using XRD, FTIR and scanning electron microscope (SEM) analyzes. To screen the relative importance of variables, parameters including pH, adsorption time, amount of adsorbent, volume of desorption solvent and stirring speed were studied using the Plackett Burman Design (PBD) using the Minitab 20 software. In the following, optimization was performed by using the central composite design (CCD), and the responses were evaluated. The calibration curve was plotted by drawing the absorbance against standard concentration. The linear dynamic range of 0.003-100 μg L-1 (DLR) and the correlation coefficient (R2) of 0.999 were obtained for chromium. Limit of detection (LOD) and limit of quantification (LOQ) for chromium were obtained equal to 0.002 and 0.0039 μg L-1, respectively. The relative standard deviation (RSD) of 6.93% and the relative recovery for chromium in real samples were obtained in the range 96.041% to 103.445% for ETAAS method. The values of detection limit (LOD) and limit of quantification (LOQ) by UV-Vis method were 0.007 and 0.021 µg L-1 respectively, and the dynamic linear range was (DLR) 0.05-50.00 µg L-1 with a correlation coefficient (R2) 0.998. The relative standard deviation (RSD) was 14.27% and the relative recovery of this method in real samples was attained from 95.103% to 103.692%.
Nayereh Rahimian; Javad Feizy; Zarrin Eshaghi
Abstract
In recent years, the presence of bisphenol A in food, drinking water, and toys is considered as a toxic compound. In this research, a Fabric-phase sorptive extraction using an organic-inorganic coating as an adsorbent was used to separate bisphenol A in different samples. The isolated bisphenol A was ...
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In recent years, the presence of bisphenol A in food, drinking water, and toys is considered as a toxic compound. In this research, a Fabric-phase sorptive extraction using an organic-inorganic coating as an adsorbent was used to separate bisphenol A in different samples. The isolated bisphenol A was measured by high-performance liquid chromatography. The organic-inorganic coating was done with other methods. Optimal conditions for selecting the type of fabric and bis phenol A extraction were obtained by the central composite design in 3 and 5 variables according to the response surface methodology. At first, the influencing factors in NFPSE such as fabric type, number of sol-gel connections, and binding time were investigated. Also, the effects of different parameters on adsorption such as sample volume, adsorption time, solution desorption volume, desorption time and pH were examined. The calibration curve in the region (0.1-15 ng.mL-1) for bisphenol A was linear with a correlation coefficient of more than 99%.The detection limit (LODs)andthe limit of quantificationwere 0.11 ng.mL-1 and 0.37 ng.mL-1 respectively.Repeatability (RSD) with three replicated experiments was 1.25%.The recovery was obtained for different samples in the range of 95 to 97 %. According to the obtained results, the method mentioned in this research can be introduced as a reproducible method with a high absorption capacity for bisphenol A determination in drinking water and toys.
Haleh Omoori Sarabi; Zarrin Eshaghi; Javad Feizy
Abstract
For the first time, hollow fiber-solid liquid phase microextraction (HF-SLPME) using multiwalled carbon nanotube- ion exchange polyurethane foam (MWCNT-PUFIX) as adsorbent along with graphite furnace atomic absorption spectrometry was used to extract and measure the anticancer drug cisplatin. In this ...
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For the first time, hollow fiber-solid liquid phase microextraction (HF-SLPME) using multiwalled carbon nanotube- ion exchange polyurethane foam (MWCNT-PUFIX) as adsorbent along with graphite furnace atomic absorption spectrometry was used to extract and measure the anticancer drug cisplatin. In this method, the nanocomposite dispersed in octanol, is located in the pores and lumen of a porous polypropylene hollow fiber, was used as the extracting phase, this method benefits from high selectivity, high sample purification and enrichment, and reducing the consumption of organic solvents. The major factors affecting the extraction efficiency were investigated. The validation of the method was assessed by linearity, limit of detection, and accuracy calculated as relative recovery percent. The calibration curve was constructed under the optimal conditions was linear in the range of 1.00-55.0 µg/mL and the detection limit was 0.5 µg/mL. This method was successfully used for analysis of biological samples and the obtained results showed that the method has good accuracy and precision.
Zahra Nazari; Zarrin Eshaghi
Abstract
In this study, an electrochemical sensor for simultaneous measurement of morphine and fentanyl based on a modified pencil graphite electrode with a semiconductor nanocrystalline structure was developed.The first layer of the sensor has a core of thioglycolic acid-bonded cadmium selenidequantum dot (TGA-CdSe), ...
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In this study, an electrochemical sensor for simultaneous measurement of morphine and fentanyl based on a modified pencil graphite electrode with a semiconductor nanocrystalline structure was developed.The first layer of the sensor has a core of thioglycolic acid-bonded cadmium selenidequantum dot (TGA-CdSe), surrounded by a second layer, zinc sulfide quantum dot (ZnS). Functionalized carbon nanotubes (FCNT) have also been used to reinforce the sensor structure (TGA-CdSe/ZnS@FCNT). Measurements were performed by differential pulse voltammetry (DPV) and cyclic voltammetry (CV).The synthesis of nanostructures was confirmed by FTIR, EDX, SEM and XRD. In order to optimize the effective factors in the performance of this sensor, the Taguchi orthogonal array (OA16) design has been utilized. TheCV voltammograms showed irreversible oxidation peaks at potentials of 0.9 V and 0.38 V for fentanyl and morphine respectively. The transfer coefficients (α) of 0.96for morphine and 0.95 for fentanyl obtained. The diffusion coefficients gained on the electrode surface by chronoamperometrywere 3.84×10-6cm2 s-1and1.615×10-6cm2s-1 for morphine and fentanyl, respectively. Under optimal conditions, the linear concentration range and detection limit for morphine were 0.08-100 μM, and 0.024 μM. For fentanyl two linear ranges of 0.02-8μM, 8-100 μM and 0.006 μM were obtained. The fabricated sensor can be well used for the simultaneous measurement of morphine and fentanyl in biological samples with acceptable relative recoveries in the range of 98.3-102.
Fatemeh Moeinpour; Danial Moodi; Haleh Sarabi-Omoori; Zarrin Eshaghi
Abstract
The aim of the present study was to develop electrochemical sensors based on pencil graphite electrode modified with green-caped ZnO, CdO nano particles and potassium tetra chloroplatinate (II), for a simple and fast simultaneous microextraction and determination of Aspirin (ASA) and Ibuprofen (IBU). ...
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The aim of the present study was to develop electrochemical sensors based on pencil graphite electrode modified with green-caped ZnO, CdO nano particles and potassium tetra chloroplatinate (II), for a simple and fast simultaneous microextraction and determination of Aspirin (ASA) and Ibuprofen (IBU). The nanoparticles were initially synthesized by the use of four vegetable extracts including garlic, onion, green onion and cabbage. The fabricated nanoparticles and platinum were then deposited on the surface of a pencil graphite electrode and was used as a working electrode in a three electrodes system. The Taguchi experimental design was employed for investigating the effects different parameters. For this purpose, a Taguchi L16 orthogonal array (OA) design was applied and the results were confirmed by the ANOVA test. The electrochemical behavior of ASA and IBU at the modified electrodes, were studied. The calibration curves were linear in the range of 5.17to 134.0 µg.mL-1 and 3.13 to 231.0 µg.mL-1 for ASA and IBU respectively. The limits of detection for ASA and IBU was calculated to be 0.50 and 0.42 µg.mL-1 respectively. The modified sensor showed good performance for simultaneous analysis of ASA and IBU in biological and pharmaceutical samples.
Nourolhoda Razavi; Amene Zendegi-Shiraz; Zarrin Eshaghi
Abstract
This study considers identification and determination of phthalates esters in cosmetic samples. The dispersive solid phase extraction was used for extraction of analytes prior to high performance liquid chromatography analysis. The solid sorbent for extraction was polyethylene glycol grafted on cupric ...
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This study considers identification and determination of phthalates esters in cosmetic samples. The dispersive solid phase extraction was used for extraction of analytes prior to high performance liquid chromatography analysis. The solid sorbent for extraction was polyethylene glycol grafted on cupric oxide nanoparticles (PEG-g-CuO-NPs). This sorbent was first synthesized and characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray(EDX) and fourier-transform infrared spectroscopy (FT-IR) then efficiently applied for extraction of analytes. The extraction conditions like amount of sorbent, kind and volume of desorption solvent, extraction and desorption time, and pH of sample solution were optimized. The validation of method carried out under optimum conditions. Linear ranges were 0.005-4 µgmL-1 with the coefficient correlation (R2) in the range of 0.9914-0.9962. The limits of detection (LODs) (3S/N) were 0.0025 to 0.005 µgmL-1 and acceptable repeatability’s (RSDs below 6.45%, n=5) obtained. Application of proposed method was investigated by extraction of phthalates in shampoo and body wash for babies which satisfaction results achieved.
Azar Sa'adi; Javad Shabani-Shayeh; Zarrin Eshaghi
Abstract
The electro-oxidation of acyclovir (ACV) was studied using synthesized Cu nanoparticles stabilized by reduced graphene oxide (Cu/RGO) modified carbon paste electrodes. In this work, leaf extract of rosemary (Rosmarinus officinalis) used as a reducing and stabilizing agent for biosynthesis of copper nanoparticles. ...
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The electro-oxidation of acyclovir (ACV) was studied using synthesized Cu nanoparticles stabilized by reduced graphene oxide (Cu/RGO) modified carbon paste electrodes. In this work, leaf extract of rosemary (Rosmarinus officinalis) used as a reducing and stabilizing agent for biosynthesis of copper nanoparticles. The Cu/RGO nanocomposite was authorized by X-ray diffraction (XRD), Fourier transformed infrared (FT-IR) spectroscopy, [1]Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM). In an alkaline solution, the electrochemical performance of Cu/RGO was checked and afterward utilized to make a modified carbon paste electrode to study the electrocatalytic oxidation of acyclovir, compared to copper modifier only. Two used methods for surveying of the oxidation reaction were cyclic voltammetry and chronoamperometry. The limit of detection for modified electrode was obtained 0.63 µM. Furthermore, the rate constant of the electrocatalytic oxidation of acyclovir was (1.80 ± 0.03) ×105 cm3mol−1s−1 and the electron-transfer coefficient was (4.00 ± 0.05) ×10–6 Cm2 s–1.
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.
Fatemeh Moeinpour; Zarrin Eshaghi
Volume 5, Issue 2 , September 2018, , Pages 9-16
Abstract
The aim of this work was indirect determination of anti-cancer drug capecitabine using complexation with platinum (IV) and determination by graphite furnace atomic absorption spectroscopy (GFAAS). For this aim at first, the complex of platinum with capecitabine was performed and the ratio of drug to ...
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The aim of this work was indirect determination of anti-cancer drug capecitabine using complexation with platinum (IV) and determination by graphite furnace atomic absorption spectroscopy (GFAAS). For this aim at first, the complex of platinum with capecitabine was performed and the ratio of drug to metal was evalutsd with several ways. In the all of these methods, the ligand to metal ratio of the Potassium hexachloroplatinate (IV) and capecitabine complex was found to be 2:1. The extraction process was carried out by the hollow fiber supported functionalized multiwalled carbon nanotubes/ polyurethane foam (fMWCNT/PUF) foam as the solid adsorbent in the solid phase microextraction mode. The amount of desorbed platinum ion has been indirectly used to measure the drug concentrations. Parameters affecting the hollow fiber-solid phase microextraction (HF-SPME) such as pH of the donor phase, donor phase volume, the sorbent type and desorption solvent were optimized. Calibration graph was plotted and a curve with a linear response range of the 3.32 to 98.17 µg mL -1 and a detection limit 0.38 µg mL -1 was obtained.
Zarrin Es’hagi; Effat Esmaeili-Shahri
Volume 5, Issue 1 , March 2018, , Pages 25-32
Abstract
Hollow fiber-solid phase microextraction (HF-SPME) technique containing multiwalled carbon nanotubes (MWCNTs) reinforced sol-gel nanocomposite coupled with UV–Vis spectrophotometry was applied for preconcentration and determination of lead, zinc and silver in water samples. In this technique, ...
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Hollow fiber-solid phase microextraction (HF-SPME) technique containing multiwalled carbon nanotubes (MWCNTs) reinforced sol-gel nanocomposite coupled with UV–Vis spectrophotometry was applied for preconcentration and determination of lead, zinc and silver in water samples. In this technique, a high efficiency sorbent containing mixture of MWCNTs and a microporous gel was injected into a piece of a polypropylene hollow fiber for in situ gelation. The method validation was included and satisfying results were obtained. It owes large surface area and porosity of the nano-adsorbent. Under the optimal conditions, linear calibration curves were established for the concentration of Pb2+, Zn2+ and Ag+ in the range of 0.2–7.0, 0.3–7.0 and 2.0–50 µg/mL respectively. The limits of detection were 0.032, 0.057 and 0.325 µg/mL for Pb2+, Zn2+ and Ag+. The relative standard deviations (RSDs) were found to be less than 8.0 %.
Zarrin Es’haghi; Zohreh Rezaeifar
Volume 2, Issue 1 , March 2015, , Pages 43-49
Abstract
This research is on the improvement of the procedure to determination of trace levels of antidepressant drug; fluoxetine in wastewaters. In this research a silica based sol-gel was applied for the extraction of fluoxetine from water samples. This two-phase technique is consisting of aqueous samples of ...
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This research is on the improvement of the procedure to determination of trace levels of antidepressant drug; fluoxetine in wastewaters. In this research a silica based sol-gel was applied for the extraction of fluoxetine from water samples. This two-phase technique is consisting of aqueous samples of fluoxetine (donor phase) and silica based nanocomposite prepared by sol-gel technique (acceptor phase). Accepter phase was held in the pores and lumen of polypropylene hollow fiber segment. Microextraction experiments were carried out in two steps; extraction from analyte samples by sorbent which is held into the hollow fiber segment and desorption of drug from hallow fiber by using of methanol. Desorbed analyte in order to measurement were offered to HPLC and UV-V is spectrophotometer for further analysis. This method is simple, fast and adopted by a majority of the instrumental methods. Extraction parameters such as sol-gel aging time, pH of donor phase, volume of donor phase, extraction time, stirring rate and effect of surfactant were investigated and optimized. The measurements were done under the optimal conditions. This technique has many advantages, such as the short extraction time, low consumption of organic solvents, elimination of carry-over effect, low limit of detection and high pre-concentration factor. The pre-concentration factor and limit of detection have been gained 3227 and 0.53 ng mL-1, respectively. The linear range and relative standard deviation are 1.0-10000.0 ng mL-1 and 4.8% (n=3), respectively.
Zarrin Es’haghi; Fatemeh Moeinpour
Volume 1, Issue 2 , September 2014, , Pages 58-64
Abstract
An efficient separation-preconcentration procedure namely hollow fiber solid/liquid phase microextraction (HF-SLPME) was developed for determination of trace amounts of palladium in water samples by differential pulse voltammetry. In this method, a hybrid sorbent utilizing functionalized nanoparticles ...
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An efficient separation-preconcentration procedure namely hollow fiber solid/liquid phase microextraction (HF-SLPME) was developed for determination of trace amounts of palladium in water samples by differential pulse voltammetry. In this method, a hybrid sorbent utilizing functionalized nanoparticles incorporated in an organic solvent was used as the extractor phase. The nanoparticle dispersed in the organic solvent is held in the pores and lumen of a porous polypropylene hollow fiber. It is in contact directly with the aqueous donor phase. The influence of the various analytical parameters such as pH, kind and amounts of nanoparticle and matrix effects, sample volume, extraction time, etc. were studied for the quantitative recoveries of the analyte ions. Under the optimized experimental conditions, the calibration curves for Pd (II) was linear from 0.1 to 500 ng/mL. The relative standard deviation for seven replicate determinations of 0.1 mg/mL palladium in the standard solutions was 3.95 %. The detection limit based on 3Sb for Pd (II) in the standard solutions was 0.01 ng/mL. The proposed method has been applied for determination of trace amounts of palladium in the real water samples and satisfactory results were obtained.
