نتایج جستجو برای: solid phase

تعداد نتایج: 753523  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس 1377

در اینجا با اصلاحی که بر مدل multi solid phase انجام شده است ، و روش حل پیشنهادی یک برنامه کامپیوتری برای پیش بینی دمای پیدایش واکس و همچنین میزان واکس تشکیل شده، در نمونه های نفتی مختلف ، ارائه شده است . در این کار از مدل فاز جامد چندگانه (multi solid phase)، که روشی مبتنی بر تحقیقات و آزمایشات انجام شده در سالهای اخیر (1991-1997) می باشد، استفاده می شود. در این مدل گفته می شود که در ابتدا فاز...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2002
yadollah yamini atefeh tamaddon

a new sensitive and selective spectrophotometric method for the determination of iron using a pvc membrane containing bathophenanthroline and dioctylphethalate as the solid phase extraction medium is investigated. fe(ii) in an aqueous sample solution is trapped on the membrane with an anion species, picrate ion and forms a complex with bathophenanthroline. the absorbance of the red-orange membr...

Journal: :international journal of environmental research 0
h. sid kalal nuclear fuel cycle school, nuclear science and technology research institute, aeoi, p.o.box 11365-3486, tehran, iran h. hoveidi graduate faculty of environment, university of tehran, p.o. box 14155-6135, tehran, iran m. thagiof nuclear fuel cycle school, nuclear science and technology research institute, aeoi, p.o.box 11365-3486, tehran, iran n. pakizevand nuclear fuel cycle school, nuclear science and technology research institute, aeoi, p.o.box 11365-3486, tehran, iran m.r. almasian nuclear fuel cycle school, nuclear science and technology research institute, aeoi, p.o.box 11365-3486, tehran, iran m.a. firoozzare nuclear fuel cycle school, nuclear science and technology research institute, aeoi, p.o.box 11365-3486, tehran, iran

a chelating resin is prepared by condensation polymerization of aniline with formaldehyde andcharacterized by ft-ir, elemental analysis and studied for the preconcentration and determination of traceplatinum ion from environmental water sample using inductively coupled plasma-atomic emission spectroscopy(icp-aes). the optimum ph value for sorption of the metal ions was 5. the maximum adsorption...

Journal: :international journal of environmental research 0

styrene is an important constituent of widely used organic solvents in industries for production of various synthetic materials. the use of solid-phase extraction (spe) has grown and is a fertile technique of sample preparation as it provides better results than those produced by liquidliquid extraction. in this study, spe has been optimized, regarding sample ph, sample concentration, sample fl...

Journal: :iranian journal of analytical chemistry 2014
sandeep jaggi usha gupta

a simple and sensitive method has been developed for the preconcentration and determination of trace level of co(ii) using uv-vis spectrophotometry. β-cyclodextrin polymer modified with 1-(2-pyridylazo)-2-naphthol (pan) is used for the preconcentration of co(ii) from samples at ph 8.5. the polymer is synthesized and characterized using elemental analysis, ft-ir and sem analysis. the factors aff...

Journal: :مجله دانشگاه علوم پزشکی قم 0
حمیدرضا حیدری hr heidari qom university of medical sciencesدانشگاه علوم پزشکی قم سید جمال الدین شاه طاهری sj shahtaheri tehran university of medical sciencesدانشگاه علوم پزشکی تهران محمود علیمحمدی m alimohammadi tehran university of medical sciencesدانشگاه علوم پزشکی تهران عباس رحیمی فروشانی a rahimi-froshani tehran university of medical sciencesدانشگاه علوم پزشکی تهران فریده گلبابایی f golbabaei tehran university of medical sciencesدانشگاه علوم پزشکی تهران

background and objectives: analytical methods for volatile organic compounds (vocs) in different samples need extraction of compounds, by applying hazardous solvents. solid phase micro-extraction (spme) is a solvent-free equilibrium extraction method, in which proper calibration can allow quantitative determinations of vocs at a very good sensitivity without the use of any organic solvent. vocs...

Journal: :iranian journal of public health 0
hr heidari dept. of occupational health sj shahtaheri dept. of occupational health, center for environmental research m alimohammadi dept .of environmental health a rahimi-froshani dept. of epidemiology and biostatistics, school of public health, tehran university of medical scien

background: determination of organic pollutants usually requires extraction of the pollutants from samples, using hazard­ous solvent. solid phase micro-extraction (spme) is a solvent-free equilibrium extraction method, in which, proper calibra­tion can allow quantitative measurements of organic pollutants at a very good sensitivity without the use of any organic sol­vent. because individual voc...

Journal: :international journal of occupational hygiene 0
nematullah kurd department of occupational health engineering, hamedan university of medical sciences, hamadan, iran. abdulrahman bahrami research centre for health sciences, faculty of health, hamedan university of medical sciences, hamadan, iran. farshid ghorbani-shahna research centre for health sciences, faculty of health, hamedan university of medical sciences, hamadan, iran. mahmoud heidari department of occupational health, faculty of health, guilan university of medical sciences, rasht, iran.

acetonitrile used as a solvent in manufactures and affects to central nervous system from inhalation exposure. the aim of this study was to develop a micro-solid phase extraction method for  the determination of acetonitrile in the air matrix. the sampling was performed with a small diameter fused silica fiber coated with a thin film of stationary phase and was subsequently desorbed and analyze...

Journal: :international journal of environmental research 2012
h. sid kalal h. hoveidi m. thagiof n. pakizevand m.r. almasian

a chelating resin is prepared by condensation polymerization of aniline with formaldehyde andcharacterized by ft-ir, elemental analysis and studied for the preconcentration and determination of traceplatinum ion from environmental water sample using inductively coupled plasma-atomic emission spectroscopy(icp-aes). the optimum ph value for sorption of the metal ions was 5. the maximum adsorption...

Journal: :journal of agricultural science and technology 0
f. ganjeizadeh rohani pharmaceutics research center, institute of neuropharmacology, kerman university of medical sciences, kerman, postal code: 7616911319, islamic republic of iran. v. mahdavi laboratory of pesticide research department, iranian research institute of plant protection, postal code: 1475744741, islamic republic of iran. m. m. aminaee laboratory of pesticide research department, iranian research institute of plant protection, postal code: 1475744741, islamic republic of iran.

pesticides are one of the major pollutants in the environment. the residue of pesticides has been reported to be at a critical level in agricultural crops, especially in greenhouse crops. tomato is considered as an important vegetable in iranian food basket and is produced in fields and greenhouses. so, the current study aimed to assess diazinon and oxydemeton-methyl levels in tomatoes sampled ...

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