Publications by authors named "Mahmoud Reza Sohrabi"

29 Publications

  • Page 1 of 1

An intelligent method based on feed-forward artificial neural network and least square support vector machine for the simultaneous spectrophotometric estimation of anti hepatitis C virus drugs in pharmaceutical formulation and biological fluid.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Dec 22;263:120190. Epub 2021 Jul 22.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.

This study proposed simple and reliable spectrophotometry method for simultaneous analysis of hepatitis C antiviral binary mixture containing sofosbuvir (SOF) and daclatasvir (DAC). This technique is based on the use of feed-forward artificial neural network (FF-ANN) and least square support vector machine (LS-SVM). FF-NN with Levenberg-Marquardt (LM) and Cartesian genetic programming (CGP) algorithms was trained to determine the best number of hidden layers and the number of neurons. This comparison demonstrated that the LM algorithm had the minimum mean square error (MSE) for SOF (1.59 × 10) and DAC (4.71 × 10). In LS-SVM model, the optimum regularization parameter (γ) and width of the function (σ) were achieved with root mean square error (RMSE) of 0.9355 and 0.2641 for SOF and DAC, respectively. The coefficient of determination (R) value of mixtures containing SOF and DAC was 0.996 and 0.997, respectively. The percentage recovery values were in the range of 94.03-104.58 and 94.04-106.41 for SOF and DAC, respectively. Statistical test (ANOVA) was implemented to compare high-performance liquid chromatography (HPLC) and spectrophotometry, which showed no significant difference. These results indicate that the proposed method possesses great potential ability for prediction of concentration of components in pharmaceutical formulations.
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http://dx.doi.org/10.1016/j.saa.2021.120190DOI Listing
December 2021

Improved spectral resolution for the rapid simultaneous spectrophotometric determination of sofosbuvir and daclatasvir as anti hepatitis C virus drugs in pharmaceutical formulation and biological fluid using continuous wavelet and derivative transform.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Apr 5;251:119429. Epub 2021 Jan 5.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.

In this study, the simultaneous spectrophotometric estimation of Sofosbuvir (SOF) and Daclatasvir (DAC) in synthetic mixtures and tablet formulation in the presence of overlapping spectra was performed based on continuous wavelet transform (CWT) and derivative spectrophotometry (DS) methods without any separation process. The Coiflet (Coif2) and Daubechies (Db3) wavelet families with wavelength of 256 nm and 218 nm were obtained as the best families for the simultaneous determination of SOF and DAC, respectively. Also, the first derivative absorption spectra revealed the best results corresponding to the analysis of SOF and DAC at 237 nm and 291 nm, respectively. The ranges of limit of detection (LOD) and limit of quantitation (LOQ) related to the CWT and DS methods were 2.45 × 10 to 0.5054 and 6.91 × 10 to 0.6027, respectively. Mean recovery values of SOF and DAC in synthetic mixtures for CWT approach were 98.55%, 98.09% and in DS method were 98.78% and 95.83%, respectively. Real samples, including Sovodak tablet and urine was used for accurate simultaneous determination of the mentioned components. Analyzing Sovodak tablet was implemented using high-performance liquid chromatography (HPLC) as a reference method that the results were near to the CWT and DS methods. In order to investigate the existence of significant differences between the methods, analysis of variance (ANOVA) test at the 95% confidence level was performed but no significant differences were observed. In addition, the amounts of SOF and DAC in the complex matrix of biological sample were well predicted by the proposed methods.
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http://dx.doi.org/10.1016/j.saa.2021.119429DOI Listing
April 2021

The application of continuous wavelet transform based on spectrophotometric method and high-performance liquid chromatography for simultaneous determination of anti-glaucoma drugs in eye drop.

Spectrochim Acta A Mol Biomol Spectrosc 2020 Dec 3;242:118777. Epub 2020 Aug 3.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.

In this study, a fast, low-cost, accurate, and precise spectrophotometric method based on the continuous wavelet transform (CWT) was assayed to determine dorzolamide (DOR) and timolol (TIM) in an eye drop sample simultaneously. Different wavelet families were investigated to select the best family for analyzing the DOR and TIM. The Mexican hat wavelet (MHW) family with the wavelength of 281 nm and Gaussian wavelet family (gaus2) in the wavelength of 267 nm were found for the simultaneous analysis of DOR and TIM, respectively. Mean recovery values of synthetic mixtures were found 97.44%±2.63 and 99.18%±4.00 for DOR and TIM, respectively. The root mean square errors (RMSE) of DOR and TIM were achieved 0.5550 and 0.3306, respectively. Eye drop as a real sample was analyzed by spectrophotometry coupled with the CWT technique, as well as high-performance liquid chromatography (HPLC) as a reference method. The obtained results were compared with each other by the one-way analysis of variance (ANOVA) test and there was no significant difference between them.
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http://dx.doi.org/10.1016/j.saa.2020.118777DOI Listing
December 2020

Simultaneous ultra-trace quantitative colorimetric determination of antidiabetic drugs based on gold nanoparticles aggregation using multivariate calibration and neural network methods.

Spectrochim Acta A Mol Biomol Spectrosc 2020 Jun 12;234:118254. Epub 2020 Mar 12.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.

In this study, a simple and rapid method was investigated for the simultaneous ultra-trace colorimetric determination of Metformin (MET) and Sitagliptin (STG) based on the aggregation of gold nanoparticles (AuNPs). The Morphology and size distribution of synthesized AuNPs before and after adding drug (Zipmet) were monitored using transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively. By adding a drug, the absorption peak was shifted from 520 to 650 nm. The colorimetric method along with partial least squares (PLS) as a multivariate calibration method, as well as neural network time series were applied to estimate MET and STG simultaneously. The percentage of the mean recovery and root mean square error (RMSE) of the test set of mixtures related to the MET and STG were obtained 99.96, 1.1301 and 99.77, 1.0106, respectively. On the other hand, the regression coefficient (R) of the training, validation, and test sets corresponding to the artificial neural network (ANN) were close to one for both components. Eventually, the proposed method was compared with a reference technique named high-performance liquid chromatography (HPLC) by analysis of variance (ANOVA) test and there was no significant difference between them.
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http://dx.doi.org/10.1016/j.saa.2020.118254DOI Listing
June 2020

Determination of 2,4-Dichlorophenoxyacetic acid in food and water samples using a modified graphene oxide sorbent and high-performance liquid chromatography.

J Environ Sci Health B 2020 20;55(4):293-300. Epub 2019 Nov 20.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.

In the present work, dispersive micro-solid phase extraction (D-μ-SPE) method using magnetic graphene oxide tert-butylamine (GO/FeO/TBA) nanocomposite, as an efficient sorbent, was applied for determining 2,4-dichlorophenoxyacetic acid (2,4-D) in water and food samples. Detection was carried out using high-performance liquid chromatography (HPLC) instrument. Influential parameters of D-μ-SPE such as sorbent and its amount, elution solvent and its volume, adsorption and desorption times and pH of sample solution were investigated and optimized. Under the optimized conditions, limit of detection and quantitation values were 0.007 and 0.02 μg/mL, respectively. Recovery data for several real samples were obtained within the range of 88.0-94.0% with a relative standard deviation (RSD) less than 7.5%. The proposed method was successfully applied to quantitative determination of 2,4-D in several vegetables and water samples.
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http://dx.doi.org/10.1080/03601234.2019.1692613DOI Listing
May 2020

Preparation and modification of forcespun polypropylene nanofibers for adsorption of uranium (VI) from simulated seawater.

Ecotoxicol Environ Saf 2019 Dec 10;186:109746. Epub 2019 Oct 10.

Department of Chemistry, Islamic Azad University, North Tehran Branch, P.O. Box, 1913674711, Tehran, Iran.

In this paper, polypropylene (PP) nanofibers were prepared using the melt forcespinning technology by a handmade device. Then, the surface of PP nanofibers was grafted through the high energy electron beams (EB) pre-irradiation method by acrylonitrile and methacrylic acid monomers with grafting percentage of 145.55%. The 92% of grafted cyano functional groups on nanofibers were converted to amidoxime groups, then modified by an alkaline solution. Characterization and surface morphology of nanofibers were investigated by Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The produced adsorbent was used to adsorb U(VI) ions from simulated seawater. The maximum adsorption was 83.24 mg/g in the optimal time of 60 min and optimal pH of 4. The optimum desorption efficiency was 80% in HCl 0.5 M. The kinetic data in optimum conditions showed that the adsorption followed an S-shaped kinetic model. The Adsorption equilibrium studies presented S-shape isotherm model that confirmed the adsorption occurs both on the adsorbent surface and in its pores The thermodynamic studies indicated spontaneous adsorption of uranyl ions and the higher efficiency adsorption at higher temperatures. The selectivity of adsorbent for metal ions followed the order V(V)>U(VI)>CO(II)>Ni(II)>Fe(II). These results shows that the prepared and modified nanofibers in this work can be considered as an effective and promising adsorbents for removal of uranium ions from seawater with high efficiency.
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http://dx.doi.org/10.1016/j.ecoenv.2019.109746DOI Listing
December 2019

Using artificial neural network and multivariate calibration methods for simultaneous spectrophotometric analysis of Emtricitabine and Tenofovir alafenamide fumarate in pharmaceutical formulation of HIV drug.

Spectrochim Acta A Mol Biomol Spectrosc 2019 May 23;215:266-275. Epub 2019 Feb 23.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.

Spectrophotometric analysis method based on artificial neural network (ANN), partial least squares regression (PLS) and principal component regression (PCR) models was proposed for the simultaneous determination of Emtricitabine (ETB) and Tenofovir alafenamide fumarate (TAF) in human immunodeficiency virus (HIV) drug. An artificial neural network consisting of two, five, and seven layers with 2,3,5,7, and 9 neurons was trained by applying a feed forward back-propagation learning. In this method, Levenberg-Marquardt (LM) and gradient descent with momentum and adaptive learning rate back propagation (GDX) algorithms were used. Statistical parameters indicated that the ability of LM was better than GDX algorithm. Also, root mean square error (RMSE) and recovery (%) of the PLS and PCR methods showed that PLS has worked better than PCR. The proposed models were compared to the high- performance liquid chromatography (HPLC) as a reference method. Furthermore, the obtained results of the one-way analysis of variance (ANOVA) test at the 95% confidence level represented that there was no significant difference between the proposed and reference methods.
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http://dx.doi.org/10.1016/j.saa.2019.02.077DOI Listing
May 2019

Determination of trace amounts of aromatic amines after magnetic solid-phase extraction using silver-modified Fe O /graphene nanocomposite.

J Sep Sci 2019 May 20;42(9):1777-1785. Epub 2019 Mar 20.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.

In this work, a fast and simple magnetic dispersive solid phase extraction methodology was developed utilizing [email protected] [email protected] nanocomposite as an efficient magnetic nanosorbent for preconcentration and determine of five aromatic amines in water samples. The sorbent was characterized by diverse characterization techniques. After the extraction, high-performance liquid chromatography with UV detection was utilized to analysis the aromatic amines. The effects of different factors on the extraction process were studied thoroughly via design of experiment and desirability function. Detection limits and linear dynamic ranges were obtained in the range of 0.10-0.20 and 0.3-300 μg/L, respectively. The relative standard deviations (n = 5) were in the range of 4.3-6.5%. Eventually, the method was employed for determination of target aromatic amines in various water samples.
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http://dx.doi.org/10.1002/jssc.201800896DOI Listing
May 2019

Preparation and characterization of a new sawdust/MNP/PEI nanocomposite and its applications for removing Pb (II) ions from aqueous solution.

Water Sci Technol 2018 Dec;78(12):2469-2480

Department of Chemistry, Islamic Azad University, North Tehran Branch, P.O. Box 1913674711, Tehran, Iran E-mail:

A new sawdust/magnetite nanoparticles/polyethyleneimine (SD/MNP/PEI) nanocomposite was synthesized by grafting polyethyleneimine (PEI) to magnetic sawdust. Features of SD/MNP/PEI were characterized using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). SD/MNP/PEI was used as an adsorbent for the removal of lead (Pb (II)) from aqueous solution. The effects of independent variables including pH of solution, adsorbent dose and contact time were performed and adsorption isotherms were obtained. Experimental results show that priority effective variables were pH and the amount of nanocomposite, and it was found that the sorption capacity increases with the increasing phase contact time. The adsorption process followed the Langmuir adsorption isotherm. Although SD and SD/MNP do not show a high affinity for the adsorption of Pb (II) in aqueous media, polyethyleneimine cross-linked on SD/MNP showed 40 and 66% increases, respectively, in the adsorption of Pb (II) compared to the SD and SD/MNP. It was found that SD/MNP/PEI removes more efficiently lead ions from aqueous solutions than the SD, SD/MNP. Desorption of the lead from the SD/MNP/PEI was conducted. It was proved that SD/MNP/PEI has excellent properties and can be used as a sorbent of multi-use.
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http://dx.doi.org/10.2166/wst.2018.521DOI Listing
December 2018

Optimization of ultrasonic assisted extraction of fatty acids from Aesculus hippocastanum fruit by response surface methodology.

Food Chem 2019 Jan 24;271:762-766. Epub 2018 Jul 24.

Department of Phytochemistry and Essential Oil Technology, Faculty of Pharmaceutical Chemistry, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran.

The effectiveness of ultrasound-assisted extraction (UAE) of Aesculus hippocastanum fruit oil was investigated using methanol as a solvent. The study compared extraction yields using UAE and methanol with soxhlet. The effects of three extraction parameters, namely temperature, time and the ratio of solvent (volume) to plant material (weight) were optimized using both a Box-Behnken design (BBD) and response surface methodology (RSM). The highest extraction yields were obtained for UAE at 60 °C and 56.5 min with a ratio of solvent to plant material weight of 45:1. The extraction yield using UAE varied by 21.82% (w/ w) but was, regardless, significantly greater than Soxhlet extraction.
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http://dx.doi.org/10.1016/j.foodchem.2018.07.144DOI Listing
January 2019

Electrospun composite PLLA/Oyster shell scaffold enhances proliferation and osteogenic differentiation of stem cells.

Biologicals 2018 Jul 2;54:33-38. Epub 2018 Jun 2.

Stem Cell Technology Research Center, Tehran, Iran.

In bone tissue engineering, bioceramics are of the most widely used materials for treatment of bone defects clinically. The composites of bioceramic/polymer fibrous scaffolds have been designed and developed to fulfill the mechanical and biological requirements of the damaged tissue. In the present study, oyster shell (OS) as a bioceramic in combination with the biodegradable and biocompatible poly (l-lactide) has been used to prepare a new tissue-engineered composite. The morphology, porosity, water contact angle and mechanical properties of scaffolds were investigated. Mesenchymal stem cells were also cultured on fabricated scaffolds to evaluate their potential to support cell proliferation and osteogenic differentiation. The SEM results indicated that the electrospun scaffolds were nanostructured and the OS were oriented along the fiber axis. The tensile strength and also the increased surface hydrophilicity of scaffolds after plasma treatment were suitable for tissue engineering applications. MTT assay demonstrated that the fabricated scaffolds were capable of supporting stem cell attachment and proliferation. Biomineralization measurements demonstrated the enhanced osteogenic differentiation of stem cells on composite PLLA/OS scaffolds. Taken together, these scaffolds were shown to hold promising potential for the treatment of bone defects in vivo.
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http://dx.doi.org/10.1016/j.biologicals.2018.04.006DOI Listing
July 2018

Use of continuous wavelet transform approach for simultaneous quantitative determination of multicomponent mixture by UV-Vis spectrophotometry.

Spectrochim Acta A Mol Biomol Spectrosc 2018 Aug 8;201:306-314. Epub 2018 May 8.

Department of Chemistry, Faculty of Chemistry, Azad University, North Tehran Branch, P.O. Box 1913674711, Tehran, Iran.

In the present paper, a multicomponent analysis approach based on spectrophotometry method was developed for simultaneous determination of Guaifenesin (GU), Chlorpheniramine (CHL) and Pseudoephedrine (PSE) without any separation steps. The method under study is signal processing method based on Continuous Wavelet Transform (CWT) coupled with zero cross point technique. In this paper, CWT method was tested by synthetic ternary mixtures and was applied to the commercial cough syrup as a real sample and assessed by applying the standard addition technique. For demonstrate the accuracy of the results, other applications of signal processing, such as Derivative Transform (DT), Partial Least Squares (PLS) regression and Principal Components Regression (PCR) were used as comparative methods. Afterwards, the obtained results from analyzing the cough syrup by all methods were compared to the High-Performance Liquid Chromatography (HPLC) as a reference method. One-way analysis of variance test at 95% confidence level showed no significant differences between CWT and other applications.
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http://dx.doi.org/10.1016/j.saa.2018.05.020DOI Listing
August 2018

A detailed structural study of cytotoxicity effect of ionic liquids on the leukemia rat cell line IPC-81 by three dimensional quantitative structure toxicity relationship.

Ecotoxicol Environ Saf 2018 Aug;158:256-265

College of Sciences, Faculty of Chemistry, University of Tehran, Tehran, Iran. Electronic address:

In the present study, a very thorough and in-depth three-dimensional quantitative structure-toxicity relationship (3D-QSTR) analysis has been implemented to make a correlation between the structural information of the ionic liquids (ILs) and their cytotoxicity towards Leukemia rat cell line IPC-81, as one of the ILs' toxicological consequences. To do this, alignment free GRid-INdependent Descriptors (GRINDs), which were derived from molecular interaction fields (MIFs), were correlated to the cytotoxicity values by partial least squares (PLS) and support vector regression (SVR). Genetic algorithm (GA), as a powerful linear tool, was used to select the best and interpretative subset of variables for the predictive model building. The selected variables with the capability to screen the effective structural features, showed direct and inverse contribution to the cytotoxicity. In silico modeling can reduce the amount of cellular testing necessary by predicting the toxicological functions of the chemical structures. Acceptable predictions of both internal and external validation sets made it possible to develop the predictive models for a large set of 269 diverse ILs containing 9 cationic cores and 44 types of anions. The constructed 3D-QSTR models use simple and interpretable descriptors to provide an in-depth and mechanistic interpretation of structural characteristics. This helps provide a clear understanding of the cytotoxicity effects of the understudy ILs. The effects of the nature of the cations, anions, and substituents on the cytotoxicities were evaluated and discussed.
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http://dx.doi.org/10.1016/j.ecoenv.2018.04.040DOI Listing
August 2018

Chemometric simultaneous determination of Sofosbuvir and Ledipasvir in pharmaceutical dosage form.

Spectrochim Acta A Mol Biomol Spectrosc 2018 Apr 6;194:141-151. Epub 2018 Jan 6.

Department of Chemistry, Faculty of Science, Islamic Azad University, Karaj branch, P.O. Box: 31485-313, Karaj, Iran.

Partial least squares (PLS), different families of continuous wavelet transform (CWT), and first derivative spectrophotometry (DS) techniques were studied for quantification of Sofosbuvir (SFB) and Ledipasvir (LDV) simultaneously without separation step. The components were dissolved in Acetonitrile and the spectral behaviors were evaluated in the range of 200 to 400nm. The ultraviolet (UV) absorbance of LDV exhibits no interferences between 300 and 400nm and it was decided to predict the LDV amount through the classic spectrophotometry (CS) method in this spectral region as well. Data matrix of concentrations and calibrated models were developed, and then by applying a validation set the accuracy and precision of each model were studied. Actual concentrations versus predicted concentrations plotted and good correlation coefficients by each method resulted. Pharmaceutical dosage form was quantified by developed methods and the results were compared with the High Performance Liquid Chromatography (HPLC) reference method. Analysis Of Variance (ANOVA) in 95% confidence level showed no significant differences among methods.
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http://dx.doi.org/10.1016/j.saa.2018.01.011DOI Listing
April 2018

The application of artificial neural networks and support vector regression for simultaneous spectrophotometric determination of commercial eye drop contents.

Spectrochim Acta A Mol Biomol Spectrosc 2018 Mar 5;193:297-304. Epub 2017 Dec 5.

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran. Electronic address:

In the present study, artificial neural networks (ANNs) and support vector regression (SVR) as intelligent methods coupled with UV spectroscopy for simultaneous quantitative determination of Dorzolamide (DOR) and Timolol (TIM) in eye drop. Several synthetic mixtures were analyzed for validating the proposed methods. At first, neural network time series, which one type of network from the artificial neural network was employed and its efficiency was evaluated. Afterwards, the radial basis network was applied as another neural network. Results showed that the performance of this method is suitable for predicting. Finally, support vector regression was proposed to construct the Zilomole prediction model. Also, root mean square error (RMSE) and mean recovery (%) were calculated for SVR method. Moreover, the proposed methods were compared to the high-performance liquid chromatography (HPLC) as a reference method. One way analysis of variance (ANOVA) test at the 95% confidence level applied to the comparison results of suggested and reference methods that there were no significant differences between them. Also, the effect of interferences was investigated in spike solutions.
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http://dx.doi.org/10.1016/j.saa.2017.11.056DOI Listing
March 2018

Photocatalytic degradation of Direct yellow 86 diazo dye using sulfanilic acid-modified TiO in aqueous suspensions.

Water Sci Technol 2017 Oct;76(7-8):1992-2002

Department of Chemistry, Islamic Azad University, North Tehran Branch, P.O. Box 1913674711, Tehran, Islamic Republic of Iran.

This study synthesized sulfanilic acid (SA)-modified TiO nanocomposites and used them as an effective photocatalyst for Direct yellow 86 diazo dye removal from aqueous solution. This novel nanocomposite (SA/TiO) was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy and X-ray diffraction. The results showed the formation of SA/TiO nanocatalyst. The photocatalytic activity of the modified photocatalyst was examined by degradation of Direct yellow 86 (GE) under UV and visible light. The effects of five parameters, the concentration of GE, dosage of SA/TiO nanocomposite, UV light irradiation intensity, pH and visible light illumination, on the removal of GE using SA/TiO nanocomposite were studied. The highest GE removal was determined at pH of 9, nanocomposite dosage of 0.15 g/l and initial GE concentration of 50 mg/l at the constant temperature of 25 °C. However, the results showed that the GE removal rate increased as the UV light intensity increased. In addition, an enhancement in the photodegradation rate was observed with visible light illumination. The adsorption trends of GE at various initial concentrations followed the Langmuir isotherm model.
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http://dx.doi.org/10.2166/wst.2017.339DOI Listing
October 2017

Artificial Neural Networks (ANN) for the Simultaneous Spectrophotometric Determination of Fluoxetine and Sertraline in Pharmaceutical Formulations and Biological Fluid.

Iran J Pharm Res 2017 ;16(2):478-489

Department of Chemistry, Faculty of Chemistry, Islamic Azad University, North Tehran Branch, Tehran, Iran.

Simultaneous spectrophotometric estimation of Fluoxetine and Sertraline in tablets were performed using UV-Vis spectroscopic and Artificial Neural Networks (ANN). Absorption spectra of two components were recorded in 200-300 nm wavelengths region with an interval of 1 nm. The calibration models were thoroughly evaluated at several concentration levels using the spectra of synthetic binary mixture (prepared using orthogonal design). Three layers feed-forward neural networks using the back-propagation algorithm (B.P) has been employed for building and testing models. Several parameters such as the number of neurons in the hidden layer, learning rate and the number of epochs were optimized. The Relative Standard Deviation (RSD) for each component in real sample was calculated as 1.06 and 1.33 for Fluoxetine and Sertraline, respectively. The results showed a very good agreement between true values and predicted concentration values. The proposed procedure is a simple, precise and convenient method for the determination of Fluoxetine and Sertraline in commercial tablets.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5603857PMC
January 2017

New model for prediction binary mixture of antihistamine decongestant using artificial neural networks and least squares support vector machine by spectrophotometry method.

Spectrochim Acta A Mol Biomol Spectrosc 2017 07 5;182:105-115. Epub 2017 Apr 5.

Department of Chemistry, Azad University, Shahreza Branch, Shahreza, Isfahan, Iran. Electronic address:

In the present study, artificial neural networks (ANNs) and least squares support vector machines (LS-SVM) as intelligent methods based on absorption spectra in the range of 230-300nm have been used for determination of antihistamine decongestant contents. In the first step, one type of network (feed-forward back-propagation) from the artificial neural network with two different training algorithms, Levenberg-Marquardt (LM) and gradient descent with momentum and adaptive learning rate back-propagation (GDX) algorithm, were employed and their performance was evaluated. The performance of the LM algorithm was better than the GDX algorithm. In the second one, the radial basis network was utilized and results compared with the previous network. In the last one, the other intelligent method named least squares support vector machine was proposed to construct the antihistamine decongestant prediction model and the results were compared with two of the aforementioned networks. The values of the statistical parameters mean square error (MSE), Regression coefficient (R), correlation coefficient (r) and also mean recovery (%), relative standard deviation (RSD) used for selecting the best model between these methods. Moreover, the proposed methods were compared to the high- performance liquid chromatography (HPLC) as a reference method. One way analysis of variance (ANOVA) test at the 95% confidence level applied to the comparison results of suggested and reference methods that there were no significant differences between them.
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http://dx.doi.org/10.1016/j.saa.2017.04.001DOI Listing
July 2017

Fabrication of sulfated nanofilter membrane based on carboxymethyl cellulose.

Water Sci Technol 2016 Dec;74(11):2611-2619

Department of Chemistry, Ahar Branch, Islamic Azad University, Ahar, Iran E-mail:

The aim of this study is to prepare sulfated carboxymethyl cellulose (SCMC) nanofilter membrane using sulfur trioxide pyridine complex (SO/pyridine) as sulfating agent and glutaraldehyde (GA) as a crosslinking agent onto polysulfone supporting membrane. The prepared nanofilter was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, atomic force microscopy and zeta potential. To evaluate the prepared nanofilter, various amounts of SO/Pyridine were used and efficiency of them was investigated. The results showed that increasing the sulfate groups raised the flux from 13.87 to 29.54 L/(m·h), whereas percentage rejection was increased during the separation of salt aqueous solutions and then decreased. It can be concluded that, SCMC-GA-2 (with molar ratio of SO/pyridine to CMC of 1) shows high separation efficiency in acidic conditions and improves the hydrophilicity and charge density of the filter.
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http://dx.doi.org/10.2166/wst.2016.441DOI Listing
December 2016

Optimizing Cu(II) removal from aqueous solution by magnetic nanoparticles immobilized on activated carbon using Taguchi method.

Water Sci Technol 2016 ;74(1):38-47

Department of New Materials, Institute of Science and High Technology and Environmental Science, Graduate University of Advanced Technology, Kerman, Iran.

This study synthesized magnetic nanoparticles (Fe(3)O(4)) immobilized on activated carbon (AC) and used them as an effective adsorbent for Cu(II) removal from aqueous solution. The effect of three parameters, including the concentration of Cu(II), dosage of Fe(3)O(4)/AC magnetic nanocomposite and pH on the removal of Cu(II) using Fe(3)O(4)/AC nanocomposite were studied. In order to examine and describe the optimum condition for each of the mentioned parameters, Taguchi's optimization method was used in a batch system and L9 orthogonal array was used for the experimental design. The removal percentage (R%) of Cu(II) and uptake capacity (q) were transformed into an accurate signal-to-noise ratio (S/N) for a 'larger-the-better' response. Taguchi results, which were analyzed based on choosing the best run by examining the S/N, were statistically tested using analysis of variance; the tests showed that all the parameters' main effects were significant within a 95% confidence level. The best conditions for removal of Cu(II) were determined at pH of 7, nanocomposite dosage of 0.1 gL(-1) and initial Cu(II) concentration of 20 mg L(-1) at constant temperature of 25 °C. Generally, the results showed that the simple Taguchi's method is suitable to optimize the Cu(II) removal experiments.
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http://dx.doi.org/10.2166/wst.2016.152DOI Listing
February 2017

The application of continuous wavelet transform and least squares support vector machine for the simultaneous quantitative spectrophotometric determination of Myricetin, Kaempferol and Quercetin as flavonoids in pharmaceutical plants.

Spectrochim Acta A Mol Biomol Spectrosc 2016 Jan 29;152:443-52. Epub 2015 Jul 29.

Department of Chemistry, Faculty of Chemistry, Azad University, North Tehran Branch, P.O. Box 1913674711, Tehran, Iran. Electronic address:

Flavonoids are γ-benzopyrone derivatives, which are highly regarded in these researchers for their antioxidant property. In this study, two new signals processing methods been coupled with UV spectroscopy for spectral resolution and simultaneous quantitative determination of Myricetin, Kaempferol and Quercetin as flavonoids in Laurel, St. John's Wort and Green Tea without the need for any previous separation procedure. The developed methods are continuous wavelet transform (CWT) and least squares support vector machine (LS-SVM) methods integrated with UV spectroscopy individually. Different wavelet families were tested by CWT method and finally the Daubechies wavelet family (Db4) for Myricetin and the Gaussian wavelet families for Kaempferol (Gaus3) and Quercetin (Gaus7) were selected and applied for simultaneous analysis under the optimal conditions. The LS-SVM was applied to build the flavonoids prediction model based on absorption spectra. The root mean square errors for prediction (RMSEP) of Myricetin, Kaempferol and Quercetin were 0.0552, 0.0275 and 0.0374, respectively. The developed methods were validated by the analysis of the various synthetic mixtures associated with a well- known flavonoid contents. Mean recovery values of Myricetin, Kaempferol and Quercetin, in CWT method were 100.123, 100.253, 100.439 and in LS-SVM method were 99.94, 99.81 and 99.682, respectively. The results achieved by analyzing the real samples from the CWT and LS-SVM methods were compared to the HPLC reference method and the results were very close to the reference method. Meanwhile, the obtained results of the one-way ANOVA (analysis of variance) test revealed that there was no significant difference between the suggested methods.
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http://dx.doi.org/10.1016/j.saa.2015.07.073DOI Listing
January 2016

Removal of diazo dye Direct Red 23 from aqueous solution using zero-valent iron nanoparticles immobilized on multi-walled carbon nanotubes.

Water Sci Technol 2015 ;71(9):1367-74

Department of Chemistry, Islamic Azad University, North Tehran Branch, P.O. Box 1913674711, Tehran, I.R. Iran E-mail:

The present study immobilized nanoscale zero-valent iron (nZVI) on multi-walled carbon nanotubes (MWCNTs) to enhance the reactivity of nZVI and prevent its aggregation. This novel composite (nZVI/MWCNT) was characterized by scanning electron microscopy and X-ray diffraction. The results showed that nZVI particles dispersed on the surface of the MWCNTs. The composite was used to remove the diazo dye Direct Red 23 from aqueous solution. The effects of nZVI to MWCNT mass ratio, nanocomposite content, solution pH, initial dye concentration and temperature were studied. The optimum nZVI/MWCNT mass ratio was 1:3. Batch experiments suggest that degradation efficiency decreased as the initial dye concentration increased and increased as the nanocomposite content increased, decreasing the pH from 8 to 4. The reaction followed a pseudo-first-order model under the operational conditions investigated in this study.
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http://dx.doi.org/10.2166/wst.2015.106DOI Listing
November 2015

Removal of methylene blue, a basic dye, from aqueous solutions using nano-zerovalent iron.

Water Sci Technol 2014 ;70(1):24-31

Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran E-mail:

In this research, the preparation of nanoparticles of Fe(0) (nano-zerovalent iron, NZVI) as adsorbent is discussed and the capability of adsorbing methylene blue (MB) is studied. The morphology of the adsorbent was evaluated with transmission electron microscopy. Batch studies were performed to delineate the influence of various experimental parameters such as pH, adsorbent dosage, initial dye concentration, temperature and contact time. Optimum conditions for MB removal were found to be pH 9.5, adsorbent dosage of 0.5 g L(-1) and equilibrium time of 1 min. The experimental equilibrium data were adjusted by the adsorption isotherms from Langmuir and Freundlich models, and their equilibrium parameters were determined. The adsorption of MB dye by NZVI obeyed both the Freundlich and Langmuir isotherm. The adsorption capacity of NZVI for MB in terms of monolayer adsorption was 208.33 mg g(-1).
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http://dx.doi.org/10.2166/wst.2014.189DOI Listing
September 2014

Spectra resolution for simultaneous spectrophotometric determination of lamivudine and zidovudine components in pharmaceutical formulation of human immunodeficiency virus drug based on using continuous wavelet transform and derivative transform techniques.

Talanta 2014 May 4;122:223-8. Epub 2014 Feb 4.

Department of Chemistry, Faculty of Chemistry, Azad University, North Tehran Branch, P.O. Box 1913674711, Tehran, Iran.

In the present paper, two spectrophotometric methods based on signal processing are proposed for the simultaneous determination of two components of an anti-HIV drug called lamivudine (LMV) and zidovudine (ZDV). The proposed methods are applied to synthetic binary mixtures and commercial pharmaceutical tablets without the need for any chemical separation procedures. The developed methods are based on the application of Continuous Wavelet Transform (CWT) and Derivative Spectrophotometry (DS) combined with the zero cross point technique. The Daubechies (db5) wavelet family (242 nm) and Dmey wavelet family (236 nm) were found to give the best results under optimum conditions for simultaneous analysis of lamivudine and zidovudine, respectively. In addition, the first derivative absorption spectra were selected for the determination of lamivudine and zidovudine at 266 nm and 248 nm, respectively. Assaying various synthetic mixtures of the components validated the presented methods. Mean recovery values were found to be between 100.31% and 100.2% for CWT and 99.42% and 97.37% for DS, respectively for determination of LMV and ZDV. The results obtained from analyzing the real samples by the proposed methods were compared to the HPLC reference method. One-way ANOVA test at 95% confidence level was applied to the results. The statistical data from comparing the proposed methods with the reference method showed no significant differences.
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http://dx.doi.org/10.1016/j.talanta.2014.01.012DOI Listing
May 2014

Experimental design and response surface modelling for optimization of vat dye from water by nano zero valent iron (NZVI).

Acta Chim Slov 2013 ;60(4):853-60

In this study, NZVI particles was prepared and studied for the removal of vat green 1 dye from aqueous solution. A four-factor central composite design (CCD) combined with response surface modeling (RSM) to evaluate the combined effects of variables as well as optimization was employed for maximizing the dye removal by prepared NZVI based on 30 different experimental data obtained in a batch study. Four independent variables, viz. NZVI dose (0.1-0.9 g/L), pH (1.5-9.5), contact time (20-100 s), and initial dye concentration (10-50 mg/L) were transform to coded values and quadratic model was built to predict the responses. The significant of independent variables and their interactions were tested by the analysis of variance (ANOVA). Adequacy of the model was tested by the correlation between experimental and predicted values of the response and enumeration of prediction errors. The ANOVA results indicated that the proposed model can be used to navigate the design space. Optimization of the variables for maximum adsorption of dye by NZVI particles was performed using quadratic model. The predicted maximum adsorption efficiency (96.97%) under the optimum conditions of the process variables (NZVI dose 0.5 g/L, pH 4, contact time 60 s, and initial dye concentration 30 mg/L) was very close to the experimental value (96.16%) determined in batch experiment. In the optimization, R2 and R2adj correlation coefficients for the model were evaluated as 0.95 and 0.90, respectively.
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February 2014

Simultaneous spectrophotometric determination of metformin hydrochloride and glibenclamide in binary mixtures using combined discrete and continuous wavelet transforms.

Anal Sci 2011 ;27(10):1037-41

Faculty of Chemistry, Islamic Azad University, Tehran North Branch, Tehran, Iran.

In this work, a combined discrete and continuous wavelet transform analysis was developed for simultaneous spectrophotometric determinations of metformin hydrochloride and glibenclamide, two antidiabetic drugs, in binary mixtures without any chemical pretreatment. Absorption spectra were subjected to the 4-level db4 discrete wavelet transform (DWT) for signal de-noising. Selected continuous wavelet transform (CWT) families (rbio3.1 with scaling factor, a = 80, and gaus2, a = 60) were applied on these de-noised signals. Finally, a zero-crossing technique was used for the construction of calibration curves for both drugs. The proposed method was validated by analyzing synthetic mixtures of the investigated drugs with various concentrations. The amount of metformin hydrochloride and glibenclamide were determined by using CWT amplitudes in zero-crossing points. The mean recovery values of metformin hydrochloride and glibenclamide were found between 98.6-102.0 and 97.9-102.4% for rbio3 and 98.3-101.2 and 97.1-101.4% for gaus2 families, respectively. The obtained results showed that the developed method is a simple, rapid and precise procedure for the simultaneous determination of metformin hydrochloride and glibenclamide in binary mixtures.
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http://dx.doi.org/10.2116/analsci.27.1037DOI Listing
January 2012

Simultaneous spectrophotometric determination of cyproterone acetate and ethinyl estradiol in tablets using continuous wavelet and derivative transform.

Spectrochim Acta A Mol Biomol Spectrosc 2010 Sep 6;77(1):107-11. Epub 2010 May 6.

Department of Chemistry, Faculty of Chemistry, Azad University, North Tehran Branch, P.O. Box 1913674711, Tehran, Iran.

In this study a zero crossing technique based on continuous wavelet transform (CWT) as well as classical derivative spectrophotometry (CDS) is presented for simultaneous determination of cyproterone acetate and ethinyl estradiol in binary mixtures and commercial dosage of drug, without using prior chemical pre-treatment. Absorption spectra were recorded in the wavelength range 200-400 nm. Absorbance data were subjected to various mother wavelets from continuous wavelet transform family to find the optimum point of the wavelet signal processing (Matlab 7.5) gaus 15 and morl wavelet functions with scaling factor, a=70 and 3rd derivative with Deltalambda=10 nm, were selected. Optimum value of scaling factor was chosen to obtain an appropriate calibration for each method. The validation of proposed methods was investigated by several synthetic mixtures and obtained results were successfully compared among each other. Mean recovery values were found between 96.93% and 101.7% for CWT and 95.55% and 104.22% for DS, respectively for the determination of cyproterone acetate and ethinyl estradiol in synthetic mixtures. The developed methods are rapid, precise and easy to apply for the analysis of overlapping signals of the components in the mixtures. Obtained results from the CWT were compared to those yielded by CDS which were in good agreement and therefore led to a successful determination.
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http://dx.doi.org/10.1016/j.saa.2010.04.034DOI Listing
September 2010

Continuous wavelet and derivative transform applied to the overlapping spectra for the quantitative spectrophotometric multi-resolution of triamterene and hydrochlorothiazide in triamterene-H tablets.

Talanta 2010 Jun 27;81(4-5):1821-5. Epub 2010 Mar 27.

Faculty of Chemistry, Azad University, North Tehran Branch, Tehran, Iran.

In present paper, continuous wavelet transform as well as first and second derivative spectrophotometry methods are proposed for simultaneous quantitative analysis of triamterene and hydrochlorothiazide without the time-consuming extraction step. In the wavelet transform method, different wavelet families were tested and subsequently coiflets wavelet family (coif1) and reverse biorthogonal wavelet family (rbio 2.8) were selected and applied under the optimal conditions for simultaneous analysis. The two above mentioned methods are based upon use of the continuous wavelet and derivative transforms of the spectra and measurement at zero-crossing wavelengths. Validation of the developed methods was confirmed by analyzing various synthetic mixtures of the investigated drugs. The experimental results obtained from the continuous wavelet transform approach were statistically compared with those yielded by derivative spectrophotometry methods and therefore led to successful results.
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http://dx.doi.org/10.1016/j.talanta.2010.03.040DOI Listing
June 2010
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