Search for: high-performance-liquid-chromatography
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    Polypropylene-based microextraction method for determination of fluoxetine in human urine samples

    , Article Analytical Letters ; Volume 45, Issue 13 , 2012 , Pages 1777-1785 ; 00032719 (ISSN) Bagheri, H ; Marzancola, M. G ; Es'haghi, A ; Sharif University of Technology
    A polypropylene (PP) sheet was successfully applied as an extracting medium for trace enrichment of fluoxetine (FLX) from urine samples, followed by high performance liquid chromatography-fluorescence detection (HPLC-FD). The extraction medium was a square, 1 × 1 cm2 piece of polypropylene membrane sheet that was conditioned in methanol. The extraction process was conveniently carried out using a 5 mL urine sample. After extraction, the PP sheet was withdrawn and transferred to a glass vial for performing the desorption process using 210 μL organic solvent. After complete drying, the residue was dissolved in 50 μL of methanol and an aliquot of 20 μL was, finally, injected into the HPLC... 

    Application of Diazonium Salts for Grafting the Sol-gel Based Sorbents: A New Approach Towards Unbreakable SPME

    , M.Sc. Thesis Sharif University of Technology Bayat, Parisa (Author) ; Bagheri, Habib (Supervisor)
    A novel application of diazonium salts for grafting the sol-gel based sorbents was sucessfully introduced. Preparation of unbrekable sorbents has been on highly demand and sough after by many researches for several years. However, there are a few achivements in this regard, but it still remains as a big challenge.Regarding to this issue, diazonium salts were sucessfully applied for functionalizing the different substrates, in which there is no limitation in selection of substrates. Different substrates, metallic and non metallic, such as copper, brass, stailess steel and PTFE were chosen to be functionalized by chemical or electrochemical reduction of 4-Amino phenyl acetic acid. Then,... 

    High-Throughput Sample Preparation on a 96-Well Plate and LC-MS Analysis of Thimerosal in Biological Products

    , M.Sc. Thesis Sharif University of Technology Khakinejad, Mahdiar (Author) ; Bagheri, Habib (Supervisor) ; Eshaghi, Ali (Supervisor)
    Thiomersal is an organomercury compound. This compound is a well established antiseptic and antifungal agent. It has been used as a preservative in vaccines, immuno-globulin preparations, skin test antigens, antivenins, ophthalmic and nasal products, and tattoo inks. Thiomersal is very toxic by inhalation, ingestion, and in contact with skin, with a danger of cumulative effects. It is also very toxic to aquatic organisms and may cause long-term adverse effects in aquatic environments.
    Thiomersal's main use is as an antiseptic and antifungal agent in vaccines. In multidose injectable drug delivery systems, it prevents serious adverse effects such as the Staphylococcus infection that,... 

    Liquid-liquid-liquid microextraction and high performance liquid Chromatography for Seperation and Determination of Estrogens in Aquatic Media

    , M.Sc. Thesis Sharif University of Technology Maleki, Hossein (Author) ; Bagheri, Habib (Supervisor)
    Liquid-liquid-liquid microextraction (LLLME) is a new miniaturized liquid extraction to preconcentrate and purify for ionizable analytes. In LLLME firstly analytes extracted in an organic phase, and subsequently back-extracted into a second aqueous phase. Main advantages of LLME are their speed, simplicity, negligible volume of solvents, analytical precision, short sample preparation and low cost. This technique was shown to be an efficient preconcentration method for the extraction of estrone and estriol from biological samples. A basic microdrop in the tip of microsyringe was fixed in the organic layer over the sample solution. After extraction for a preset time, the microdrop was... 

    Synthesis and Optimization of Endohedral Metall of Ullerene Production in Arc Reactor Applying Vertical Graphite Electrodes

    , M.Sc. Thesis Sharif University of Technology Zarepour Jevinani, Morteza (Author) ; Ghanbari, Bahram (Supervisor)
    One of the considerable issues in fullereneresearch is low yield of endohedral fullerene production.In this project, synthesis and optimization of endohedral metallofullereneproduction was undertaken byarc reactor applying vertical graphite electrodes, using vaporizing composite lanthanum-oxide-graphite-dopped rod. Increasing the efficiency of endohedral fullerrene production in sootwas followed applyingcarbide formation in electrode which was studied by X-ray diffraction(XRD), thermogravimetric analysis(TGA) and infrared (IR) spectroscopy. In addition, as a simple and fast method, the liquid column chromatography was applied in separation and purification of fullerenes as well as endohedral... 

    On-line SPE of Clodinafop Propargyl Traces from Aquatic Media Using Electrospun Polyamide Nanofibers Disks

    , M.Sc. Thesis Sharif University of Technology Asgari, Sara (Author) ; Bagheri, Habib (Supervisor)
    An on-line solid phase extraction (SPE) method coupled with high performance liquid chromatography (HPLC) was developed using electrospun polyamide (PA) nanofibers as the extractin medium for trace determination of clodinafop propargyl herbicide in environmental aqueous samples. The sufficient numbers of disc sheets were cut from the electrospun PA mat and used as packing material in a cartridge. The homogeneity and the porosity of the prepared PA sheet were studied using the scanning electron microscopy (SEM) and the observed nanofiber diameters and lengths proved that the prepared sorbent possess a high aspect ratio. Major parameters affecting the extraction efficiency were optimized. The... 

    Electrospun Functionalized Silica / Polyvinyl Alcohol Nanofibers for On-Line μ-Solid Phase Extraction of Estrone and Estradiol in Biological Samples

    , M.Sc. Thesis Sharif University of Technology Taheri, Navid (Author) ; Bagheri, Habib (Supervisor)
    A method for determination of estrogens in biological samples was developed. This method was based on high performance liquid chromatography using online micro-solid phase extraction with 25 mg sorbent synthesized by electrospining of silica/PVA nanofibers. Poly (vinyl alcohol) (PVA) is an easily electrospun polymer with unique properties such as biocompatibility, processability, and hydrophilicity. Silica is biocompatible, thermally stable, and comparatively inert. Incorporation of silica with PVA produces hybrids with enhanced thermal and chemical stability in sample media and elution solvents without relinquishing the biocompatibility of PVA. The sufficient numbers of disc sheets were cut... 

    Novel Approach Towards Mechanical and Thermal Resistant Capillary Microextraction by Sol-Gel Technique in On-Line Combination with High Performance Liquid Chromatography

    , Ph.D. Dissertation Sharif University of Technology Piri-Moghadam, Hamed (Author) ; Bagheri, Habib (Supervisor)
    In this thesis, a new approach was developed to achieve mechanical and chemical resistant capillary microextraction (CME) in on-line combination with high performance liquid chromatography (HPLC) based on sol-gel technology. This thesis is divided into three chapters:
    First chapter contains of two parts. Overcoming the lack of mechanical stability of the substrate of CME by replacing the fused silica by copper tubings was the main objective of the first part. Self-assembled monolayers technique was employed to functionalize the copper tube followed by chemical bonding of the sorbent on the inner surface of the copper tube by sol-gel technology. The prepared copper tube containing the... 

    Synthesis and Implementation of Metal-organic Frameworks Based on Chromium Metal Salt in μ-solid Phase Extraction of Anti-hypertension Drugs in Biological Samples

    , M.Sc. Thesis Sharif University of Technology Sheshkhan, Abbas (Author) ; Bagheri, Habib (Supervisor)
    Several metal-organic frameworks based on chromium metal salt and terephthalic acid were synthesized by the solvo-thermal method and modified directly using amino acids or their imidazole derivatives. Suitable characteristics of the synthesized novel MOFs led to their use as novel extracting phases for sample preparation. The sorbent’s performance in extracting anti-hypertension drugs such as eprosartan, losartan and valsartan was tested using the magnetic solid phase extraction which is a form of μ-SPE, followed by HPLC analysis. Different parameters effecting the extraction and desorption procedures were optimized to achieve the highest performance of extraction and sensitivity. Said... 

    A horizontally oriented setup for liquid-liquid-liquid microextraction of estrogens

    , Article Analytical Methods ; Volume 5, Issue 22 , 2013 , Pages 6517-6522 ; 17599660 (ISSN) Bagheri, H ; Maleki, H ; Es'Haghi, A ; Sharif University of Technology
    A horizontally oriented liquid-liquid-liquid microextraction (HOLLLME) setup was developed and applied for the isolation of two major estrogens from aquatic media. In contrast to the conventional procedure, in this setup the extracting microdrop was suspended from a horizontally positioned needle in order to provide much higher stability to the extracting phase. The developed HOLLLME approach was applied to isolate two major selected estrogens from aquatic media followed by high performance liquid chromatography-ultraviolet (HPLC-UV) determination. Estrogens were, initially, extracted from water samples into hexane and subsequently, the back extraction stage was performed with 6 μL of sodium... 

    Supercritical extraction of phenanthrene in the crossover region

    , Article Journal of Chemical and Engineering Data ; Volume 50, Issue 1 , 2005 , Pages 49-51 ; 00219568 (ISSN) Esmaeilzadeh, F ; Goodarznia, I ; Sharif University of Technology
    An experimental flow-type apparatus has been tested for the separation of phenanthrene from a mixture of solids (phenanthrene, anthracene, and carbazole) and also from anthracene oil of the Isfahan Coal Tar Refining Company based on retrograde crystallization phenomena in supercritical carbon dioxide. The results show that by exploiting the crossover effect it is possible to obtain (82 and 24) mass % of phenanthrene from the solid mixture and anthracene oil, respectively, with a single temperature cycle  

    Sol-gel-based molecularly imprinted xerogel for capillary microextraction

    , Article Analytical and Bioanalytical Chemistry ; Volume 404, Issue 5 , September , 2012 , Pages 1597-1602 ; 16182642 (ISSN) Bagheri, H ; Piri-Moghadam, H ; Sharif University of Technology
    Springer  2012
    A novel molecularly imprinted xerogel (MIX) based on organically modified silica (ORMOSIL) was successfully prepared for on-line capillary microextraction (CME) coupled with high-performance liquid chromatography (HPLC). The sol-gel-based xerogel was prepared using only one precursor and exhibited extensive selectivity towards triazines along with significant thermal and chemical stability. Atrazine was selected as a model template molecule and 3-(trimethoxysilyl)propylmethacrylate (TMSPMA) as a precursor in which the propylmethacrylate moiety was responsible for van der Waals, dipole-dipole, and hydrogen-bond interactions with the template. This moiety plays a key role in creation of... 

    Analysis of bioactive constituents of saffron using ultrasonic assisted emulsification microextraction combined with high-performance liquid chromatography with diode array detector: A chemometric study

    , Article RSC Advances ; Volume 5, Issue 33 , 2015 , Pages 26246-26254 ; 20462069 (ISSN) Chaharlangi, M ; Parastar, H ; Malekpour, A ; Sharif University of Technology
    Royal Society of Chemistry  2015
    In recent years, there has been an increasing interest in the analysis of the major active components of saffron owing to their significant role in various industries, such as food, medicine and perfume. In other words, analysis of the major active components of saffron can give complete information about its chemical composition, which can be used as a reliable index for the quality control of different saffron samples (i.e., natural and commercial). The aim of the present work was to develop a simple, low cost, efficient and comprehensive strategy for the extraction and analysis of the bioactive components of saffron. In this regard, ultrasonic-assisted solvent extraction (UASE) combined... 

    Separation of phenolic glycolipids in mycobacterium bovis BCG by reversed-phase high performance liquid chromatography

    , Article Pakistan Journal of Pharmaceutical Sciences ; Volume 22, Issue 2 , 2009 , Pages 145-149 ; 1011601X (ISSN) Salimi, M ; Pourabdi, L ; Zakeri, M ; Abdipour, N ; Sharif University of Technology
    A crude phenolic glycolipid extract from Mycobacterium bovis BCG was fractionated by column chromatography. A reversed-phase high performance liquid chromatography (HPLC) method with UV detection at 275nm was developed for simultaneous detection and separation of phenolic glycolipids (PGLs) in Mycobacterium bovis BCG. This analysis provides a good resolution. Different solvent systems and columns for HPLC were compared. A system composed of acetonitrile-water in the ratio of 0→80% at a flow rate of 0.8 mL/min and C8 analytical column were found to be optimum for HPLC of the phenolic glycolipids. This simple method is therefore appropriate to purify these compounds present in M. bovis extract... 

    Analysis of alternative new pesticide (fluopyram, flupyradifurone, and indaziflam) residues in pistachio, date, and soil by liquid chromatography triple quadrupole tandem mass spectrometry

    , Article Soil and Sediment Contamination ; Volume 30, Issue 4 , 2021 , Pages 373-383 ; 15320383 (ISSN) Mahdavi, V ; Keikavousi Behbahan, A ; Moradi, F ; Aboul Enein, H. Y ; Sharif University of Technology
    Bellwether Publishing, Ltd  2021
    Fluopyram, flupyradifurone, and indaziflam are novel systemic pesticides developed by Bayer. Based on available data, these pesticides appears to have a favorable safety profile in the case of pesticide residue problems. Herein, we report an effective analytical method for the determination of novel pesticides were developed using ultra-high performance liquid chromatography with tandem mass spectrometry coupled with a quick, easy, cheap, effective, rugged, and safe procedure. These target compounds were extracted with acetonitrile and cleaned up with PSA, and were separated successfully between 10.2 and 18.3 min using a C18 chromatographic column connected to an electrospray ionization... 

    Preparation of amine–modified lignin and its applicability toward online micro–solid phase extraction of valsartan and losartan in urine samples

    , Article Journal of Chromatography A ; Volume 1643 , 2021 ; 00219673 (ISSN) Taherzadeh Ghahfarrokhi, M ; Zeinali, S ; Bagheri, H ; Sharif University of Technology
    Elsevier B.V  2021
    In the present work, with the focus on an environmentally–friendly approach, some gels were prepared by synthesizing amine–modified lignin, extracted from sugarcane bagasse, and further esterification and subsequent freeze–drying. These lignin–based gels were implemented as extractive phases in an online micro–solid phase extraction (μSPE) setup in conjunction with high performance liquid chromatography (HPLC) with UV detector. The developed method was used for analytical determination of valsartan and losartan in urine samples. To study the effect of the functionalization process, the efficiency of the unmodified lignin and the functionalized lignin were compared both in the absence and the... 

    Characterization of Essential Oil Components of Green and Black Cardamoms Using GC-MS Combined with Chemometric Resolution Techniques & Quantification of Two Types of Taxus Using Fast Liquid Chromatography Combined with MCR

    , M.Sc. Thesis Sharif University of Technology karimi, Mehdi (Author) ; Jalali Heravi, Mehdi (Supervisor)
    Progress in analysis of multicomponent mixtures and processes focused on the interpretation of the multivariate responses, rely on the combination of sophisticated instrumental techniques and suitable chemometric methods. Among the present chemometric method, curve resolution techniques have a wide application in the analysis of multicomponent mixtures and processes. Chemometric resolution techniques are used in the present work. At the first, Essential oil of green and black cardamoms was extracted by hydrodistillation and was analyzed by gas chromatography–mass spectrometry (GC-MS). Due to the fact that the essential oils are complex mixtures, strong overlap is observed between the peaks.... 

    Modified Lignin Natural Polymer and Graphene Oxide Aerogels and Valuation of their Performance in Sample Preparation

    , M.Sc. Thesis Sharif University of Technology Taherzadeh, Mehrnoush (Author) ; Bagheri, Habib (Supervisor)
    A green aerogel was prepared by synthesizing amine-modified lignin from sugarcane bagasse and further modification by CS2 and subsequent freeze drying. This aerogel was implemented as an extractive phase in a home-made online micro solid phase extraction-high performance liquid chromatography (μSPE-HPLC) setup for analyzing cardiovascular drugs (valsartan and losartan) in urine samples. To study the effect of functionalization, bare or functionalized lignin powders were mixed with graphene oxide (GO) at different ratios while functionalized lignin showed the highest efficiency. The prepared aerogel was analyzed using CHNS elemental analysis, and FT-IR spectrometry. Effects of influencing... 

    Interpenetrating Polymer Networks as New Sorbent for Microextraction Techniques

    , M.Sc. Thesis Sharif University of Technology Khalilzadeh, Mehrdad (Author) ; Bagheri, Habib (Supervisor)
    In this project, silica and polystyrene based interpenetrating polymer networks (IPNs) were used as a sorbent for microextraction in packed sorbent for having both of the polymer’s properties at the same time. Interpenetrating polymer networks were synthesized with the simultaneous method and three different kind of interpenetrating polymer networks were prepared including full-interpenetrating polymer networks, covalent semi-interpenetrating polymer networks and non-covalent semi-interpenetrating polymer networks. To investigate extraction efficiency of prepared sorbents, 41 compounds including environmental pollutants and biomolecules were chosen. Studies showed that interpenetrating... 

    Preparation of a naltrexone HCL potentiometric sensor and its application to pharmaceutical analysis and drug determination in biological fluids

    , Article Journal of Food and Drug Analysis ; Volume 19, Issue 4 , 2011 , Pages 445-451+539 ; 10219498 (ISSN) Ghorbani Bidkorbeh, F ; Shahrokhian, S ; Mohammadi, A ; Dinarvand, R ; Sharif University of Technology
    A novel ion selective electrode is fabricated for naltrexone HCl and used in pharmaceutical analysis and drug determination in biological fluids without complicated pretreatments and extractions, using direct potentiometry. The naltrexone complex with sodium tetraphenyl borate (NaTPB) is obtained by in situ soaking PVC membrane electrode in an 1 × 10 -3 M naltrexone solution. The sensor exhibited fast, reproducible and linear sub-Nernstian response over concentration range of 1 × 10 -5 - 1 × 10 -3 M with a detection limit of 5 × 10 -6 M. The membrane sensor was successfully applied to the determination of naltrexone in capsules as well as for its determination in urine and plasma samples