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    Chemometrics-assisted GC-MS analysis of volatile and semi-volatile constituents of elettaria cardamomum

    , Article Food Analytical Methods ; Vol. 7, issue. 9 , 2014 , pp. 1745-1754 ; ISSN: 1936-9751 Asadollahi-Baboli, M ; Mani-Varnosfaderani, A ; Sharif University of Technology
    Abstract
    Multivariate curve resolutions (MCR) along with other chemometric techniques are proposed to improve the analysis of Iranian Elettaria cardamomum (E. cardamom) essential oil with gas chromatography-mass spectrometry (GC-MS). In addition, multivariate curve resolution-alternating least squares (MCR-ALS) is used to obtain pure elution and mass spectral profiles for the components present in each chromatographic segment as well as their relative concentrations. This strategy was also used to overcome the problems of baseline offset, asymmetric peaks, retention time shifts, and overlapped and embedded peaks occurring during GC-MS analysis. The analysis of GC-MS data revealed that 42 components... 

    The use of Bayesian nonlinear regression techniques for the modelling of the retention behaviour of volatile components of Artemisia species

    , Article SAR and QSAR in Environmental Research ; Volume 23, Issue 5-6 , 2012 , Pages 461-483 ; 1062936X (ISSN) Jalali Heravi, M ; Mani-Varnosfaderani, A ; Taherinia, D ; Mahmoodi, M. M ; Sharif University of Technology
    2012
    Abstract
    The main aim of this work was to assess the ability of Bayesian multivariate adaptive regression splines (BMARS) and Bayesian radial basis function (BRBF) techniques for modelling the gas chromatographic retention indices of volatile components of Artemisia species. A diverse set of molecular descriptors was calculated and used as descriptor pool for modelling the retention indices. The ability of BMARS and BRBF techniques was explored for the selection of the most relevant descriptors and proper basis functions for modelling. The results revealed that BRBF technique is more reproducible than BMARS for modelling the retention indices and can be used as a method for variable selection and... 

    Towards greater mechanical, thermal and chemical stability in solid-phase microextraction

    , Article TrAC - Trends in Analytical Chemistry ; Volume 34 , 2012 , Pages 126-138 ; 01659936 (ISSN) Bagheri, H ; Piri-Moghadam, H ; Naderi, M ; Sharif University of Technology
    Abstract
    Solid-phase microextraction (SPME) is a fast, solvent-free technique, which, since its introduction in the 1990s, has been increasingly applied to sample preparation in analytical chemistry. Conventional SPME fibers are fabricated by making a physical bond between the usual silica substrate and the polymeric coatings. However, some applications are limited, as the lifetime and the stability of conventional SPME fibers cannot meet the demands of analyzing relatively non-volatile compounds with more polar moieties. There have been attempts to analyze less volatile compounds by increasing the thermal, physical and chemical stability of the fibers. In this review, we present some new... 

    Adsorption of petroleum monoaromatics from aqueous solutions using granulated surface modified natural nanozeolites: Systematic study of equilibrium isotherms

    , Article Water, Air, and Soil Pollution ; Volume 217, Issue 1-4 , 2011 , Pages 611-625 ; 00496979 (ISSN) Seifi, L ; Torabian, A ; Kazemian, H ; Bidhendi, G. N ; Azimi, A. A ; Charkhi, A ; Sharif University of Technology
    Abstract
    Petroleum monoaromatics including benzene, toluene, ethylbenzene, and xylenes (BTEX) are among the notorious volatile organic compounds that contaminate water and soil. In this study, a surfactant- modified natural zeolite and its relevant granulated nanozeolites were evaluated as potential adsorbents for removal of petroleum monoaromatics from aqueous solutions. All experiments performed in batch mode at constant temperature of 20°C and pH of 6.8 for 48 h. The results revealed that the amount of BTEX uptake on granulated zeolites nanoparticles were remarkably higher than the parent micron size natural zeolite (in the order of four times). The isotherms data were analyzed using five models... 

    Odor Emission from Evaporation Ponds:Investigation of Pollution Measures

    , M.Sc. Thesis Sharif University of Technology Zeighami, Mohammad Amir (Author) ; Kariminia, Hamid-Reza (Supervisor) ; Borghei, Mehdi (Supervisor)
    Abstract
    Odor caused by the release of volatiles from refinery waste, causing environmental pollution and health hazards may occur. Refinery wastewater project in Saeakhs (Khangiran) has been studied. Contaminated water in evaporation ponds at the plant accumulates due to the large volume of incoming water and slow evaporation in summer the water will smell unpleasant. Odor from the ponds due to wind scattered around the refinery and residents will be put at risk. Several tests to identify the source of the odor was designed and implemented. Among these methods, microalgae growth, the import of oil products such as aromatic compounds or mercaptans, and bacterial growth, for each of the hypotheses... 

    Desion an Appropriate Supported transition Metals Oxide Over Alumina Catalyst for Deep Oxidation of Cyclohexane in Air

    , M.Sc. Thesis Sharif University of Technology Jafari, Masoumeh (Author) ; Khorashe, Farhad (Supervisor) ; Kazemini, Mohammad (Supervisor)
    Abstract
    Volatile Organic Compounds (VOCs) have become an important source of air pollution due to their extended use as solvents in many industrial processes. Aliphatic and aromatic VOC removal from contaminated air can be achieved by a variety of methods including catalytic oxidation, adsorption, and biological treatment. Catalytic oxidation is often the preferred process due to its low cost and high efficiency. Supported transition metal catalysts are effective and inexpensive catalysts for VOC removal from contaminated air. The objective of this project was to prepare low cost transition metal catalysts (Fe, Ni, Co, and Cu) supported on alumina for catalytic oxidation of cyclohexane (as a... 

    Evaluation Of Nano-sorbents for Removal of Ethyl-benzene from Exhaust of Soil Vapor Extraction (SVE)System

    , M.Sc. Thesis Sharif University of Technology Jangodaz, Elnaz (Author) ; Sayf Kordi, Ali Akbar (Supervisor) ; Alaiee, Ebrahim (Supervisor) ; Tasharrofi, Saiedeh (Co-Advisor)
    Abstract
    Volatile organic compounds are major cause of air pollution. In this work, Nano porous material named MIL-101(Fe), MIL-53(Fe), MIL-101(Fe) and MIL-88(Fe) as an adsorbent for the removal of ethyl benzene have been synthesized hydrothermally. The materials were characterized by Fourier-transform infrared (FT-IR) spectroscopy, Surface Analysis Systems (ASAP), and x-ray diffraction (XRD) analysis. Adsorption isotherms of ethyl benzene on the materials were measured experimentally in case of 0-1000ppm concentration of ethyl benzene in air and pressure 1 atmosphere. The mixture of air and VOC (ethyl benzene) with concentration of 100, 250, 500 and 1000 ppm and flow rate of 400, 1030, 1525 and 2025... 

    Roles of inorganic oxide nanoparticles on extraction efficiency of electrospun polyethylene terephthalate nanocomposite as an unbreakable fiber coating

    , Article Journal of Chromatography A ; Volume 1375 , 2015 , Pages 8-16 ; 00219673 (ISSN) Bagheri, H ; Roostaie, A ; Sharif University of Technology
    Elsevier  2015
    Abstract
    In the present work, the roles of inorganic oxide nanoparticles on the extraction efficiency of polyethylene terephthalate-based nanocomposites were extensively studied. Four fiber coatings based on polyethylene terephthalate nanocomposites containing different types of nanoparticles along with a pristine polyethylene terephthalate polymer were conveniently electrospun on stainless steel wires. The applicability of new fiber coatings were examined by headspace-solid phase microextraction of some environmentally important volatile organic compound such as benzene, toluene, ethylbenzene and xylene (BTEX), as model compounds, from aqueous samples. Subsequently, the extracted analytes were... 

    Polybutylene terephthalate-nickel oxide nanocomposite as a fiber coating

    , Article Analytica Chimica Acta ; Volume 863, Issue 1 , 2015 , Pages 20-28 ; 00032670 (ISSN) Bagheri, H ; Roostaie, A ; Sharif University of Technology
    Elsevier  2015
    Abstract
    A highly efficient polybutylene terephthalate (PBT)-based nanocomposite containing nickel oxide nanoparticles was synthesized by electrospinning technique and used as a fiber coating for solid phase microextraction. The influential morphological parameters and capability of the prepared nanocomposite including the NiO content, the coating time, the PBT concentration and applied voltage were considered for optimization. The applicability of the synthesized fiber coating was examined by headspace solid phase micro extraction and gas chromatography mass spectrometry detection of some volatile organic compounds in aqueous samples. Among the synthesized nanocomposites and pristine PBT nanofibers,... 

    A combined micro-solid phase-single drop microextraction approach for trace enrichment of volatile organic compounds

    , Article Analytical Methods ; Volume 7, Issue 16 , Jun , 2015 , Pages 6514-6519 ; 17599660 (ISSN) Bagheri, H ; Zare, M ; Piri Moghadam, H ; Es haghi, A ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    An attempt was made to combine μ-solid phase extraction and headspace single drop microextraction techniques and use their advantages for trace determination of some volatile organic compounds in aqueous samples. After performing the two-step preconcentration approach, the desired analytes were determined by gas chromatography-mass spectrometry. A resorcinol-formaldehyde-based xerogel was used as the extraction medium in the μ-solid phase extraction (μ-SPE) method. Then, the extracted BTEX was eluted with a rather large amount of methanol. To remove the laborious process including solvent evaporation and further reconstitution, which is usually accompanied by loss of analytes and accuracy,... 

    Modeling of Ground-Level Ozone Concentrations in Tehran using CMAQ Model

    , M.Sc. Thesis Sharif University of Technology Hossein Nia, Bardia (Author) ; Arhami, Mohammad (Supervisor)
    Abstract
    Every year, air pollution is causing immense harm to humans and the environment. To cause Air pollution, several factors are involved. Among these are the sources of emissions such as factories, power plants and Cars, meteorological factors such as temperature and wind speed and geographical conditions such as altitude, postal and looming around the area, land slope and soil type region. The aim of this study is to identify factors that affect the ozone concentration in Tehran, which could help identifying other secondary pollutants. For this purpose, a combination tailored to the geography of Tehran using CMAQ-WRF-SMOKE-made programs. This model includes four intervals each of which lasting... 

    Self-modeling curve resolution techniques applied to comparative analysis of volatile components of Iranian saffron from different regions

    , Article Analytica Chimica Acta ; Volume 662, Issue 2 , 2010 , Pages 143-154 ; 00032670 (ISSN) Jalali Heravi, M ; Parastar, H ; Ebrahimi Najafabadi, H ; Sharif University of Technology
    Abstract
    Volatile components of saffron from different regions of Iran were extracted by ultrasonic-assisted solvent extraction (USE) and were analyzed by gas chromatography-mass spectrometry (GC-MS). Self-modeling curve resolution (SMCR) was proposed for resolving the co-eluted GC-MS peak clusters into pure chromatograms and mass spectra. Multivariate curve resolution-objective function minimization (MCR-FMIN) and multivariate curve resolution-alternating least square (MCR-ALS) were successfully used for this purpose. The accuracy of the qualitative and quantitative results was improved considerably using SMCR techniques. Comparison of the results of saffron from different regions of Iran showed... 

    Removal of Volatile Chlorinated Compounds (TCE,PCE) from Groundwater with Nanostructure of NZVI

    , M.Sc. Thesis Sharif University of Technology Ghasemipoor, Amir (Author) ; Bastani, Darioush (Supervisor) ; Seifkordi, Ali Akbar (Supervisor) ; Samiee, Leila (Supervisor) ; Dastgheib, Mohammad Mehdi (Co-Advisor)
    Abstract
    In recent years, the reductive dehalogenation of the chlorinated hydrocarbons using nanoscale zerovalent iron (nZVI) represents a promising approach for underground remediation. Regarding commercialization of this technique, instability and unknown nature of nZVI particle are still challenging tasks that should be considered.
    In the current work, Nanoscale zero-valent iron (nZVI) and palladized iron (Pd/Fe) bimetallic particles were synthesized and employed to react with chlorinated compound (PCE) in water to investigate its degradation behaviors. The results show that the reactant ratio, stabilizer amount and temperature are the main parameters with the considerable effect on PCE... 

    Emission Estimation for Volatile Organic Compounds (VOCs) form Evaporation Ponds in the Upstream Oil and Gas Industry

    , M.Sc. Thesis Sharif University of Technology Hadivi, Pouya (Author) ; Arhami, Mohammad (Supervisor)
    Abstract
    This study aims to estimate the emission rate of Volatile Organic Components (VOCs) and hazardous air pollutants from the surface of evaporation ponds in oil and gas upstream industries. With respect to the irrecoverable consequences of such emissions, the emission of air pollutants in the oil and gas upstream industries are alarming. Hence, estimation of the pollutants’ emission and surface pollution monitoring are needed for controlling and decreasing of air pollutants in oil and gas upstream industries and also presenting and performing suitable and efficient solutions. The studied ponds in this research include 4 ponds in the oil and gas upstream industries which have been used for... 

    A single–step synthesized supehydrophobic melamine formaldehyde foam for trace determination of volatile organic pollutants

    , Article Journal of Chromatography A ; Volume 1525 , 2017 , Pages 10-16 ; 00219673 (ISSN) Bagheri, H ; Zeinali, S ; Baktash, M. Y ; Sharif University of Technology
    Abstract
    Superhydrophobic materials have attracted many attentions in recent years while their application in sample preparation remained almost intact. In this project, a rough surface of melamine formaldehyde foam was silanized by chemical deposition of trichloromethylsilane to form a highly porous and superhydrophobic material, presumably a suitable medium for extracting non–polar compounds such as benzene and its methyl derivatives. The prepared sorbent was packed in a needle for the headspace needle–trap microextraction of benzene, toluene, ethylbenzene and xylenes (BTEX). Major parameters associated with the extraction/desorption processes were considered for optimization. Under the optimized... 

    Design and Construction the Low Cost Catalyst for Removal of VOCs from Air

    , M.Sc. Thesis Sharif University of Technology Fahimirad, Mahdi (Author) ; Shaygan Salek, Jalaloddin (Supervisor)
    Abstract
    Nowadays, increased pollutants in the air threat the society health condition and Volatile Organic Compounds (VOCs) are the most hazardous ones among them. In the present study, catalytic oxidation as a prominent of the VOCs removal method from air, have attracted attentions due to high removal efficiency and suitable kinetic reaction. Because of its common industrial applications, toluene is intended to be eliminated through a low cost carbon supported catalyst which is synthesised in the laboratory. Construction method, carbonaceous support type, catalyst metal and its load, calcination temperature and time are among influencing design characteristics. A combination of Impregnation and... 

    A core–shell titanium dioxide polyaniline nanocomposite for the needle-trap extraction of volatile organic compounds in urine samples

    , Article Journal of Separation Science ; Volume 40, Issue 9 , 2017 , Pages 1985-1992 ; 16159306 (ISSN) Banihashemi, S ; Bagheri, H ; Sharif University of Technology
    Wiley-VCH Verlag  2017
    Abstract
    We synthesized a titanium dioxide–polyaniline core–shell nanocomposite and implemented it as an efficient sorbent for the needle-trap extraction of some volatile organic compounds from urine samples. Polyaniline was synthesized, in the form of the emeraldine base, dissolved in dimethyl acetamide followed by diluting with water at pH 2.8, using the interfacial polymerization method. The TiO2 nanoparticles were encapsulated inside the conducting polymer shell, by adapting the in situ dispersing approach. The surface characteristics of the nanocomposite were investigated by Fourier transform infrared spectrometry, scanning electron microscopy, and transmission electron microscopy. After... 

    Oxidation of toluene in humid air by metal oxides supported on Γ-alumina

    , Article Journal of Hazardous Materials ; Volume 333 , 2017 , Pages 293-307 ; 03043894 (ISSN) Esmaeilirad, M ; Zabihi, M ; Shayegan, J ; Khorasheh, F ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    Monometallic and bimetallic supported metal oxides catalysts on γ-alumina were prepared by heterogeneous deposition-precipitation. The γ-alumina used as a support was synthesized by the sol-gel and the co-precipitation methods. Supports and catalysts were characterized by Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The performance of the prepared catalysts was studied for total oxidation of toluene in air at different relative humidity and oxidation temperatures. Efficiency of bimetallic catalysts for deep oxidation of toluene was... 

    Spatiotemporal description of BTEX volatile organic compounds in a middle eastern megacity: tehran study of exposure prediction for environmental health research (Tehran SEPEHR)

    , Article Environmental Pollution ; Volume 226 , 2017 , Pages 219-229 ; 02697491 (ISSN) Amini, H ; Hosseini, V ; Schindler, C ; Hassankhany, H ; Yunesian, M ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
    Abstract
    The spatiotemporal variability of ambient volatile organic compounds (VOCs) in Tehran, Iran, is not well understood. Here we present the design, methods, and results of the Tehran Study of Exposure Prediction for Environmental Health Research (Tehran SEPEHR) on ambient concentrations of benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX. To date, this is the largest study of its kind in a low- and middle-income country and one of the largest globally. We measured BTEX concentrations at five reference sites and 174 distributed sites identified by a cluster analytic method. Samples were taken over 25 consecutive 2-weeks at five reference sites (to be used for... 

    A systematic review of land use regression models for volatile organic compounds

    , Article Atmospheric Environment ; Volume 171 , 2017 , Pages 1-16 ; 13522310 (ISSN) Amini, H ; Yunesian, M ; Hosseini, V ; Schindler, C ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
    Abstract
    Various aspects of land use regression (LUR) models for volatile organic compounds (VOCs) were systematically reviewed. Sixteen studies were identified published between 2002 and 2017. Of these, six were conducted in Canada, five in the USA, two in Spain, and one each in Germany, Italy, and Iran. They were developed for 14 different individual VOCs or groupings: benzene; toluene; ethylbenzene; m-xylene; p-xylene; (m/p)-xylene; o-xylene; total BTEX; 1,3-butadiene; formaldehyde; n-hexane; total hydro carbons; styrene; and acrolein. The models were based on measurements ranging from 22 sites in El Paso (USA) to 179 sites in Tehran (Iran). Only four studies in Rome (Italy), Sabadell (Spain),...