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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.
There is an important ratio between the stationary phase weight and the dry weight of the analyte mixture that can be applied onto the column. For silica column chromatography, this ratio lies within 20:1 to 100:1, depending on how close to each other the analyte components are being eluted.
A complication with light gas analyses that include H 2 is that He, which is the most common and most sensitive inert carrier (sensitivity is proportional to molecular mass) has an almost identical thermal conductivity to hydrogen (it is the difference in thermal conductivity between two separate filaments in a Wheatstone Bridge type ...
Universal detectors typically measure a bulk property (e.g., refractive index) by measuring a difference of a physical property between the mobile phase and mobile phase with solute while selective detectors measure a solute property (e.g., UV-Vis absorbance) by simply responding to the physical or chemical property of the solute. [56]
The carrier is of the identical element but is non-radioactive. The carrier and the radionuclide of interest have identical chemical properties. Typically the amount of carrier added is conventionally selected for the ease of weighing such that the accuracy of the resultant weight is within 1%.
Flow injection analysis (FIA) is an approach to chemical analysis. It is accomplished by injecting a plug of sample into a flowing carrier stream. [1] [2] [3] The principle is similar to that of Segmented Flow Analysis (SFA) but no air is injected into the sample or reagent streams..
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A separatory funnel used for liquid–liquid extraction, as evident by the two immiscible liquids.. Liquid–liquid extraction, also known as solvent extraction and partitioning, is a method to separate compounds or metal complexes, based on their relative solubilities in two different immiscible liquids, usually water (polar) and an organic solvent (non-polar).