نتایج جستجو برای: liquid liquis extraction

تعداد نتایج: 372242  

2004

The report deals with liquid-liquid distribution systems, in which one phase is aqueous, and the distribution of the component can be influenced in many cases with chemical reactions. The formulas and equations are given, by which the actual distribution ratio of the analyte at given conditions and concentrations can be predicted. The conditional extraction constants, which are essential for th...

Journal: :Clinical chemistry 1983
B T Hofreiter A C Mizera J P Allen A M Masi W C Hicok

Solid-state extraction of plasma or serum offers significant advantages over traditional liquid-liquid methods in cortisol determinations by liquid chromatography (HPLC). Sample preparation is facilitated and HPLC column contamination is minimized. Extract yield from the solid-state columns is enhanced by sample pretreatment with methanol. Cortisol values by solid-state extraction/HPLC correlat...

Journal: :journal of tethys 0

dissolved nitrogen predispersed solvent extraction (dnpdse) is a new method devised for improving the performance of equipment utilized in the solvent extraction (sx) method, especially for dilute solutions. in this method, for mixing the two phases, bubble dispersion of the organic phase (colloidal gas aphrons [cgas]) is used instead of its drop dispersion in the aqueous phase. through increas...

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...

In this research, a Dispersive Liquid-Liquid MicroExtraction (DLLME) method coupled to UV-vis spectrophotometry was developed for the indirect determination of silver ion. The method is based on the catalytic effect of the silver ion on the oxidation of congo red by potassium peroxodisulphate and extraction with DLLME procedure using chloroform (extraction solvent) containing cetyltrimethyl...

Journal: :Dalton transactions 2014
Alok Rout Koen Binnemans

A new non-fluorinated malonamide-based ionic liquid extractant was synthesized and investigated for the extraction behavior of europium(III) and other trivalent rare-earth ions from nitric acid medium. The extractant was the functionalized ionic liquid trihexyl(tetradecyl)phosphonium N,N,N',N'-tetra(2-ethylhexyl)malonate, [P66614][MA], and it was used in combination with the non-fluorinated ion...

Journal: :Journal of chromatography. A 2005
Peter Apps Margaux Lim Ah Tock

Continuous liquid-liquid extraction is a versatile, reliable and robust sample preparation technique, but there is a tendency for the solvent to make channels through the sample, causing uneven and incomplete extraction. A simple, cheap magnetic stirrer that prevents channelling improves extraction efficiency by between 2.8 and 17.6 times.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

Journal: :Talanta 2009
Aristidis N Anthemidis Kallirroy-Ioanna G Ioannou

This review aims to provide an overview of homogeneous liquid-liquid extraction (HLLE) and dispersive liquid-liquid microextraction (DLLME) methods and their potential use in inorganic analysis. Relevant applications to the determination of metal ions, metalloids and organometals are included. The phase separation mechanisms of these unconventional solvent extraction techniques are discussed. T...

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