نتایج جستجو برای: liquid microextraction

تعداد نتایج: 219504  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سمنان - دانشکده شیمی 1392

چکیده در بخش اول این پروژه دو روش میکرواستخخرا به نامهای میکرواسخخرا امولسیونی با کمک اموا فراصتتتو 1 و میکرواستتتخخرا مای – مای با کمک هوا 2 ، به عنوان دو روش میکرواستتتخخرا بدون حلال پخشکننده 3 ، برای اسخخرا برخی هیتدروکربتنهای آروماتیتک حلقوی 4 از نمونتههای آبتی بهکار گرفخه و پارامخرهای موثری همچون نوع حلال اسختتتتخرا کننده، حجم حلال اسخخرا کننده، میزان نمک، زمان تابش اموا فراصتو ، تددا...

Journal: :journal of chemical health risks 0
m. salahinejad environmental laboratory, nstri, tehran, iran f. aflaki environmental laboratory, nstri, tehran, iran

the dispersive liquid–liquid microextraction (dllme) method for determination of pb +2 and cd +2 ions in the environmental water samples was combined with inductively coupled plasma-atomic emission spectrometry (icp-aes). ammonium pyrrolidine dithiocarbamate (apdc), chloroform and ethanol were used as chelating agent, extraction solvent and disperser solvent, respectively. some effective parame...

2012
Li Zaijun Sun Xiulan Liu Junkang

Direct analysis of samples, regardless their origin, is desirable although for the majority of cases unfeasible on account of the complexity of the sample matrix, inadequate concentration of the target analytes, or even incompatibility with the detector. In these cases, a sample pretreatment step is required for interference removal and analytes separation/preconcentration. Despite valuable adv...

Journal: :analytical and bioanalytical chemistry research 0
alireza ghiasvand department of chemistry, lorestan university, khoramabad, iran afagh nasirian department of chemistry, lorestan university, khoramabad, iran samira koonani department of chemistry, lorestan university, khoramabad, iran kolsoom nouriasl department of chemistry, lorestan university, khoramabad, iran

since solid-phase and liquid-phase microextraction (spme and lpme) were introduced, as effective solvent-free methods, many efforts have been made to improve their modes and applications. however, due to limitations with sensitivity and efficiency, researchers have focused on improving the performance of their basic primary modes. in this way, in recent years, different methods such as ultrason...

Journal: :analytical and bioanalytical chemistry research 2014
m. adibmehr h. bagheri sadeghi sh. dehghan abkenar

a simple and rapid microextraction procedure based on dispersive liquid-liquid microextraction (dllme) was developed for determination and speciation of trace amounts of chromium (cr) by flame atomic absorption spectrometry (faas). in the proposed approach, chloroform and methanol were used as extraction and dispersive solvents. a new schiff's base ligand, bis(2-methoxy benzaldehyde) ethylene d...

Journal: :Journal of chromatographic science 2013
Xueju Lv Yi Hao Qiong Jia

Phthalate esters are endocrine disrupters or mutagens. They are widely used as plasticizers and can be usually found in environmental samples, such as food, soil and polluted air. However, it is difficult to directly determine phthalate esters owing to their relatively low concentration and complex matrices. Therefore, preconcentration and separation have become increasingly important. In recen...

Journal: :analytical and bioanalytical chemistry research 2016
ali daneshfar reza tabaraki raana khodakaramin tahere khezeli

a very simple, rapid and sensitive dispersive liquid-liquid microextraction (dllme) followed by gas chromatography and flame ionization detection (gc-fid) was developed for the determination of phenol and carvacrol in honey samples. a mixture of 100 µl dichloromethane (extraction solvent) and 0.5 ml acetonitrile (disperser solvent) was rapidly injected into sample solution. thereby a cloudy sol...

Journal: :international journal of nano dimension 0
k. motevalli department of applied chemistry, technical and engineering faculty, islamic azad university, south tehran branch, tehran, iran. m. zeeb department of applied chemistry, technical and engineering faculty, islamic azad university, south tehran branch, tehran, iran.

an efficient dispersive liquid-liquid microextraction using tetraalkylammonium bromide coated silver nanoparticles (dllme-agnps) prepared in chloroform has been successfully applied as electrostatic affinity probes to the microextraction and preconcentration of terazosin prior to spectrofluorimetry analysis. this technique is based on a ternary system of solvents, where appropriate amount of mi...

2004
Derrick C. Wood James M. Miller

2 Headspace sampling for gas chromatographic (GC) analysis has many advantages, the most important of which is the elimination of many interferences from the sample matrix. In addition to the standard methods for headspace sampling, the technique of solid-phase microextraction (SPME) has found wide acceptance because it is simple and inexpensive. More recently, single-drop microextraction (SDME...

Journal: :Molecules 2014
Helena Prosen

Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environme...

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