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water-analysis
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Immersed solvent microextraction of phenol and chlorophenols from water samples followed by gas chromatography-mass spectrometry
, Article Journal of Chromatography A ; Volume 1046, Issue 1-2 , 2004 , Pages 27-33 ; 00219673 (ISSN) ; Saber, A ; Mousavi, S. R ; Sharif University of Technology
2004
Abstract
A homemade immersed solvent microextraction (SME) device was successfully developed for the trace enrichment of phenols from aqueous samples. A microdrop of butyl acetate was suspended from the tip of a microsyringe needle, immersed in an aqueous spiked solution for a preset time. The microdrop was then retracted into the microsyringe and injected directly into a gas chromatography-mass spectrometry (GC-MS) injection port. Effects of different parameters such as the type of solvent, extraction time, stirring rate, and temperature were investigated and optimized. To reduce the polarity of phenols and prevent tailing effects, all the phenols were derivatized prior to extraction using acetic...
Pyrrole-based conductive polymer as the solid-phase extraction medium for the preconcentration of environmental pollutants in water samples followed by gas chromatography with flame ionization and mass spectrometry detection
, Article Journal of Chromatography A ; Volume 1015, Issue 1-2 , 2003 , Pages 23-30 ; 00219673 (ISSN) ; Mohammadi, A ; Sharif University of Technology
Elsevier
2003
Abstract
A pyrrole-based polymer was synthesized and applied as a new sorbent for solid-phase extraction (SPE) of some environmental pollutants from water samples. Polypyrrole (PPy) was synthesized by chemical oxidation of the monomer in nonaqueous solution. SPE of selected phenols, pesticides, and polyaromatic hydrocarbons (PAHs) from aqueous samples were performed using 200mg PPy. The determination was subsequently carried out by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The polymer showed much higher recoveries for aromatic compounds than aliphatics. Preconcentration of sample volumes up 1l led to acceptable recoveries for aromatic and...
Conductive polymers as new media for solid-phase extraction: Isolation of chlorophenols from water sample
, Article Journal of Chromatography A ; Volume 986, Issue 1 , 2003 , Pages 111-119 ; 00219673 (ISSN) ; Saraji, M ; Sharif University of Technology
Elsevier
2003
Abstract
Three different conductive polymers, poly-N-methylaniline (PNMA), polyaniline and polydiphenylamine were synthesised and used as sorbents for the solid-phase extraction of some phenolic compounds from water. The separation and determination was, subsequently, performed by gas chromatography-electron-capture and flame ionization detection. Among these easy-made polymers, PNMA gave better recovery for the extraction of the studied analytes. The capability of the PNMA to extract other non-polar compounds such as chloro- and methylbenzene, decane, decanol, cyclohexane and cyclohexanol was also studied. The polymer showed some sort of selectivity towards aromatic compounds than aliphatic....
Investigation and modeling of splashing in the Peirce Smith converter
, Article Chemical Product and Process Modeling ; Volume 3, Issue 1 , 2008 ; 19342659 (ISSN) ; Halali, M ; Askari, M ; Manzari, M. T ; Sharif University of Technology
2008
Abstract
To investigate the factors affecting splashing in Peirce-Smith copper converters of Sarcheshmeh copper complex, South-East Iran, a laboratory scale model with dimensions one eighth of the actual converter was designed and assembled. The model was filled with water. Air was impinged onto the water. The sequence of events was subsequently recorded using high speed cameras. Factors affecting splashing such as blowing angle, volumetric flow rate of air, and the distance of the blowers from water surface were studied. Using a value of 2.65×10-11 for Morton dimensionless number, it was found that splashing may be reduced by 75% if the air speed in the tuyeres is reduced from 155 m/s to 30 m/s...
New polymeric sorbent for the solid-phase extraction of chlorophenols from water samples followed by gas chromatography-electron-capture detection
, Article Journal of Chromatography A ; Volume 910, Issue 1 , 2001 , Pages 87-93 ; 00219673 (ISSN) ; Saraji, M ; Sharif University of Technology
2001
Abstract
A polymeric material, polyaniline, was employed as a new sorbent for solid-phase extraction (SPE) of some environmental pollutants from water samples. Chlorophenols were extracted from aqueous samples by SPE using 120 mg polyaniline and determined by gas chromatography with electron-capture detection. The acetate esters of these phenols were formed by the direct addition of acetic anhydride to the organic extractant in the presence of K2CO3. Different conditions were applied to obtain higher retaining capacity and breakthrough volumes. The results compared with those obtained by other groups. The RSD for a river water sample spiked at sub-ppb level was lower than 10% (n = 3) and detection...
Improvement of Photocatalytic Efficiency of Nano-Titania Compsites
, Ph.D. Dissertation Sharif University of Technology ; Sadrnezhad, Khatiboleslam (Supervisor)
Abstract
Semiconductor-based photo catalysts, titanium dioxide (TiO2) especially, have been extensively studied for the oxidative photo destruction of organic pollutants in wastewaters and hydrogen production as a green energy source. Much effort has been made to remove the restrictions on the use of TiO2 and challenges related to the recovery of powdery photocatalysts. In this study, copper oxide (CuO) and Zirconium oxide (ZrO2) were used to synthesize nanocomposites. Composition of TiO2/CuO and TiO2/ZrO2 with different weight percentages of second dioxide was synthesized by chemical methods and structural properties of samples were studied by X-ray diffraction and scanning electron microscopy....
Fluctuation of air-water two-phase flow in horizontal and inclined water pipelines
, Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 129, Issue 1 , 2007 , Pages 1-14 ; 00982202 (ISSN) ; Borghei, S. M ; Saidi, M. H ; Sharif University of Technology
2007
Abstract
Air in water flow is a frequent phenomenon in hydraulic structures. The main reason for air entrainment is vortices at water intakes, pumping stations, tunnel inlets, and so on. The accumulated air, in a conduit, can evolve to a different flow pattern, from stratified to pressurized. Among different patterns, slug is most complex with extreme pressure variations. Due to lack of firm relations between pressure and influential parameters, study of slug flow is very important. Based on an experimental model, pressure fluctuations inside a circular, horizontal, and inclined pipe (90 mm inside diameter and 10 m long) carrying tow-phase air-water slug flow has been studied. Pressure fluctuations...
A polypyrrole-based sorptive microextraction coating for preconcentration of malathion from aquatic media
, Article Chromatographia ; Volume 74, Issue 9-10 , 2011 , Pages 731-735 ; 00095893 (ISSN) ; Aghakhani, A ; Ayazi, Z ; Khakinezhad, M ; Sharif University of Technology
Abstract
A new micro-solid phase extraction method was developed by combining solid-phase extraction and stir bar sorptive extraction to benefit from the advantages of both techniques. A polypyrrole coating was electrochemically synthesized on the surface of an already used graphite furnace, employed in electro-thermal atomic absorption spectroscopy. The cylindrical geometry of the graphite tube provided a rather huge surface area, suitable for sorptive extraction. The novel sorbent coating was examined as an extracting medium to isolate malathion. Effects of different parameters such as extraction time, salt concentration, sample volume, desorption solvent and time were investigated and optimized....
Physico-chemical and biological characteristics of Sarabs (spring pools) in the Kermanshah Province of Iran
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 30, Issue 5 , 2006 , Pages 621-635 ; 03601307 (ISSN) ; Shayegan, S. J ; Sharif University of Technology
2006
Abstract
Sarabs (spring-fed pools) are an important natural freshwater resource in Iran where they are used for potable, agricultural and recreational purposes. A survey of 17 Sarabs was undertaken in the Province of Kermanshah to obtain data on their water quality and biology which would help inform future management of these multifunctional resources. These Sarabs differed greatly in size (50-30000m2 surface area) and were situated at altitudes of between 622 and 1697 m above sea level. The average dissolved oxygen content and pH of the water was between 4.5 and 10mg O2/1, and 6.95 and 7.6 respectively. The Sarabs differed particularly in their dissolved solids content from 100μS/cm (detectable...
Development of Microextraction Methods
for the Trace Determination of Organic Compounds in Biological and Environmental Media
,
Ph.D. Dissertation
Sharif University of Technology
;
Bagheri, Habib
(Supervisor)
Abstract
The approach of this thesis is to develop and simplify robust microextraction techniques and apply these developed methods to real samples and complex matrices. Firstly, a modified solvent microextraction with back extraction method (SME/BE) combined with high performance liquid chromatography and fluorescence detection (HPLC-FD) was developed for the determination of citalopram in human plasma. Extraction process was performed in a home-made total glass vial without using a teflon ring, usually employed in SME/BE. The evaluation results demonstrated that the calibration curve showed linearity in the range of 1.0–130.0 ng/mL which covers therapeutic window and even lower amounts which is...
On-line micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofibers
, Article Chromatographia ; Vol. 77, issue. 9-10 , May , 2014 , p. 723-728 ; Asgari, S ; Piri-Moghadam, H ; Sharif University of Technology
Abstract
An on-line extraction/determination set up was designed for micro solid-phase extraction of clodinafop propargyl from water, soil and wheat samples using electrospun polyamide nanofiber mats. The prepared mats were packed in a stainless steel tube which conveniently acted as a high-performance liquid chromatography injection loop. Influential parameters affecting the extraction efficiency were optimized using a distilled water sample fortified with 25 μg L-1 of clodinafop propargyl. An enrichment factor of 440 was achieved for clodinafop propargyl indicating the ability of the whole procedure. Under the optimum conditions, the linearity for the analyte was in the range of 6-700 μg L-1, while...
Immersed solvent microextraction of aryloxyphenoxypropionate herbicides from aquatic media
, Article International Journal of Environmental Analytical Chemistry ; Volume 93, Issue 4 , Feb , 2013 , Pages 450-460 ; 03067319 (ISSN) ; Es'haghi, A ; Es-haghi, A ; Sharif University of Technology
2013
Abstract
An immersed solvent microextraction (SME) method was successfully developed for the trace enrichment of aryloxyphenoxypropionate herbicides from aquatic media. A microdrop of toluene was used as the extraction solvent. Some important extraction parameters such as type of solvent, solvent dropsize, stirring rate, ionic strength and extraction time were investigated and optimized. The microdrop volume of 1.5 μL, a sampling time of 25 min, and use of toluene were major parameters for achieving high enrichment factors. The linearity was studied by preconcentration of 4 mL of the water samples spiked with a standard solution of aryloxyphenoxypropionates at the concentration range of 0.15 to 30 ng...
Larval habitats and biodiversity of anopheline mosquitoes (Diptera: Culicidae) in a malarious area of southern Iran
, Article Journal of Vector Borne Diseases ; Volume 49, Issue 2 , Jun , 2012 , Pages 91-100 ; 09729062 (ISSN) ; Vatandoost, H ; Oshaghi, M. A ; Charrahy, Z ; Haghdoost, A. A ; Sedaghat, M. M ; Abedi, F ; Soltani, M ; Raeisi, A ; Sharif University of Technology
JVBD
2012
Abstract
Background & objectives: Malaria is the most important mosquito-borne disease in Iran. It is endemic in south to southeastern part of the country. Knowledge about bio-ecology of vectors will support authorities for appropriate management of the disease. Bashagard district is one of the main endemic areas for malaria in south of Iran. This study was conducted to determine anopheline fauna, diversity and affinity in the area, characterization of larval habitats, and mapping their potential distribution across the district. Methods: The potential aquatic habitats for Anopheles larvae were extracted from Indian Remote Sensing Satellite (IRS) image and digital elevation model of the area using...
Magnetic nanoparticle-based micro-solid phase extraction and GC-MS determination of oxadiargyl in aqueous samples
, Article Chromatographia ; Volume 74, Issue 5-6 , 2011 , Pages 483-488 ; 00095893 (ISSN) ; Zandi, O ; Aghakhani, A ; Sharif University of Technology
Abstract
A new facile, rapid, inexpensive, and sensitive method based on magnetic micro-solid phase extraction (M-μ-SPE) coupled to gas chromatography-mass spectrometry (GC-MS) was developed for determination of the herbicide oxadiargyl in environmental water samples. The feasibility of employing non-modified magnetic nanoparticles (MNPs) as sorbent was examined and applied to perform the extraction process. Influential parameters affecting the extraction efficiency along with desorption conditions were investigated and optimized. The limit of detection (LOD, S/N = 3) and limit of quantification (LOQ, S/N = 10) of the method under optimized conditions were 0.005 and 0.030 ng mL-1, respectively. The...
Headspace solvent microextraction as a simple and highly sensitive sample pretreatment technique for ultra trace determination of geosmin in aquatic media
, Article Journal of Separation Science ; Volume 29, Issue 1 , 2006 , Pages 57-65 ; 16159306 (ISSN) ; Salemi, A ; Sharif University of Technology
2006
Abstract
A headspace solvent microextraction method was developed for the trace determination of geosmin, an odorant compound, in water samples. After performing the extraction by a microdrop of an organic solvent, the microdrop was introduced directly into a GC-MS injection port. One-at-the-time optimization strategy was applied to investigate and optimize some important extraction parameters such as type of solvent, drop volume, temperature, stirring rate, ionic strength, sample volume, and extraction time. The analytical data exhibited an RSD of less than 5% (n = 5), a linear calibration range of 5-900 ng/L (r2 > 0.998), and a detection limit of 0.8 and 3.3 ng/L using two different sets of...
Immersed solvent microextraction and gas chromatography-mass spectrometric detection of s-triazine herbicides in aquatic media
, Article Analytica Chimica Acta ; Volume 537, Issue 1-2 , 2005 , Pages 81-87 ; 00032670 (ISSN) ; Khalilian, F ; Sharif University of Technology
Elsevier
2005
Abstract
An immersed solvent microextraction (SME) method was successfully developed for the trace enrichment of s-triazine herbicides from aquatic media. A microdrop of butyl acetate was applied as the extraction solvent. After extraction, the microdrop was introduced directly into a gas chromatography-mass spectrometry (GC-MS) injection port. Some important extraction parameters such as type of solvent, extraction time, stirring rate, and temperature were investigated and optimized. The highest possible microdrop volume of 3 μl, a sampling temperature of 60°C, and use of butyl acetate are major parameters to obtain high enrichment factors. The enrichment factor and linearity was studied by...
Optimization of some experimental parameters in the electro membrane extraction of chlorophenols from seawater
, Article Journal of Chromatography A ; Volume 1216, Issue 45 , 2009 , Pages 7687-7693 ; 00219673 (ISSN) ; Khalilian, F ; Bagheri, H ; Lee, H. K ; Sharif University of Technology
2009
Abstract
An electro membrane extraction (EME) methodology was utilized to study the isolation of some environmentally important pollutants, such as chlorophenols, from aquatic media based upon the electrokinetic migration process. The analytes were transported by application of an electrical potential difference over a supported liquid membrane (SLM). A driving force of 10 V was applied to extract the analytes through 1-octanol, used as the SLM, into a strongly alkaline solution. The alkaline acceptor solution was subsequently analyzed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection. The parameters influencing electromigration, including volumes and pH of the donor and...
Second-order calibration for simultaneous determination of pharmaceuticals in water samples by solid-phase extraction and fast high-performance liquid chromatography with diode array detector
, Article Chemometrics and Intelligent Laboratory Systems ; Vol. 137, issue , 2014 , pp. 146-154 ; ISSN: 01697439 ; Parastar, H ; Sharif University of Technology
Abstract
A fast high-performance liquid chromatography-diode array detection (HPLC-DAD) approach combined to solid phase extraction (SPE) as a pre-concentration step is developed for simultaneous determination of five selected pharmaceuticals (carbamazepine, naproxen, diclofenac, gemfibrozil and mefenamic acid) in water samples. The effective factors on the efficiency of SPE procedure are optimized using faced-centered central composite design (FCCD). In addition, multi-response optimization by using Derringer's desirability function is used to find the optimum experimental conditions for extraction of analytes from well and river waters. Due to the complexity of water matrices and the presence of...
High-throughput micro-solid phase extraction on 96-well plate using dodecyl methacrylate-ethylen glycol dimethacrylate monolithic copolymer
, Article Analytica Chimica Acta ; Volume 792 , August , 2013 , Pages 59-65 ; 00032670 (ISSN) ; Es'haghi, A ; Es-haghi, A ; Mohammadkhani, E ; Sharif University of Technology
2013
Abstract
A novel high-throughput device based on 96-micro-solid phase extraction (96-μ-SPE) system was constructed for multiresidue determination of nine pesticides in aquatic samples. The extraction procedure was performed on a commercially available 96-well plate system. The extraction module consisted of 96 pieces of 1cm×3cm of cylindrically shaped stainless steel meshes. The prepared meshes were fixed in a home-made polytetrafluoroethylene-based constructed ninety-six holes block for possible simultaneous immersion of meshes into the center of individual wells. Dodecyl methacrylate and ethylene glycol dimethacrylate was copolymerized as a monolithic polymer and placed in the cylindrically shaped...
Extraction of fluoxetine from aquatic and urine samples using sodium dodecyl sulfate-coated iron oxide magnetic nanoparticles followed by spectrofluorimetric determination
, Article Analytica Chimica Acta ; Volume 692, Issue 1-2 , 2011 , Pages 80-84 ; 00032670 (ISSN) ; Zandi, O ; Aghakhani, A ; Sharif University of Technology
Abstract
A new method based on the combination of magnetic solid phase extraction (MSPE) and spectrofluorimetric determination was developed for isolation and preconcentration of fluoxetine form aquatic and biological samples using sodium dodecyl sulfate (SDS) coated Fe3O4 nanoparticles (NPs) as a sorbent. The unique properties of Fe3O4 NPs including high surface area and strong magnetism were utilized effectively in the MSPE process. Effect of different parameters influencing the extraction efficiency of fluoxetine including the amount of Fe3O4 and SDS, pH value, sample volume, extraction time, desorption solvent and time were optimized. Under optimized condition, the method was successfully applied...