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Electromembrane Extraction
Electro membrane extraction, or EME, is a miniaturized liquid-liquid extraction technique developed for sample preparation of aqueous samples prior to analysis by chromatography, electrophoresis, mass spectrometry Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is use ..., and related techniques in analytical chemistry. EME involves the use of a small supported liquid membrane (SLM) sustained in the wall of a porous hollow fiber, and application of an electrical field across the SLM. Principle Target compounds are extracted from an aqueous sample, through a µL-volume of organic solvent sustained as a thin supported liquid membrane (SLM) in the pores in the wall of a porous hollow fiber, and into an acceptor solution inside the lumen of the hollow fiber. Extraction is based on electrokine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatography
In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the ''mobile phase'', which carries it through a system (a column, a capillary tube, a plate, or a sheet) on which a material called the ''stationary phase'' is fixed. Because the different constituents of the mixture tend to have different affinities for the stationary phase and are retained for different lengths of time depending on their interactions with its surface sites, the constituents travel at different apparent velocities in the mobile fluid, causing them to separate. The separation is based on the differential partitioning between the mobile and the stationary phases. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus affect the separation. Chromatography may be preparative or analytical. The purpose of preparativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophoresis
Electrophoresis, from Ancient Greek ἤλεκτρον (ḗlektron, "amber") and φόρησις (phórēsis, "the act of bearing"), is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. Electrophoresis of positively charged particles (cations) is sometimes called cataphoresis, while electrophoresis of negatively charged particles (anions) is sometimes called anaphoresis. The electrokinetic phenomenon of electrophoresis was observed for the first time in 1807 by Russian professors Peter Ivanovich Strakhov and Ferdinand Frederic Reuss at Moscow University, who noticed that the application of a constant electric field caused clay particles dispersed in water to migrate. It is ultimately caused by the presence of a charged interface between the particle surface and the surrounding fluid. It is the basis for analytical techniques used in chemistry for separating molecules by size, charge, or binding affinity. Electropho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds. In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionized, for example by bombarding it with a beam of electrons. This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragments) are then separated accordin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Analytical Chemistry
Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separation isolates analytes. Qualitative analysis identifies analytes, while quantitative analysis determines the numerical amount or concentration. Analytical chemistry consists of classical, wet chemical methods and modern, instrumental methods. Classical qualitative methods use separations such as precipitation, extraction, and distillation. Identification may be based on differences in color, odor, melting point, boiling point, solubility, radioactivity or reactivity. Classical quantitative analysis uses mass or volume changes to quantify amount. Instrumental methods may be used to separate samples using chromatography, electrophoresis or field flow fractionation. Then qualitative and quantitative analysis can be performed, often with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid-phase Microextraction
Electro membrane extraction, or EME, is a miniaturized liquid-liquid extraction technique developed for sample preparation of aqueous samples prior to analysis by chromatography, electrophoresis, mass spectrometry Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is use ..., and related techniques in analytical chemistry. EME involves the use of a small supported liquid membrane (SLM) sustained in the wall of a porous hollow fiber, and application of an electrical field across the SLM. Principle Target compounds are extracted from an aqueous sample, through a µL-volume of organic solvent sustained as a thin supported liquid membrane (SLM) in the pores in the wall of a porous hollow fiber, and into an acceptor solution inside the lumen of the hollow fiber. Extraction is based on electrokine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraction (chemistry)
Extraction in chemistry is a separation process consisting of the separation of a substance from a matrix. Common examples include '' liquid-liquid extraction'', and ''solid phase extraction''. The distribution of a solute between two phases is an equilibrium condition described by partition theory. This is based on exactly how the analyte moves from the initial solvent into the extracting solvent. The term ''washing'' may also be used to refer to an extraction in which impurities are extracted from the solvent containing the desired compound. Types of extraction * Liquid–liquid extraction * Solid-phase extraction * Acid-base extraction * Supercritical fluid extraction * Ultrasound-assisted extraction * Heat reflux extraction * Mechanochemical-assisted extraction * Maceration * Microwave-assisted extraction * Instant controlled pressure drop extraction (DIC, from the French, Détente instantanée contrôlée) * Perstraction Laboratory applications and examples Liquid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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