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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.
A solvent reservoir may be attached at the top of the column. Two methods are generally used to prepare a column: the dry method and the wet method. For the dry method, the column is first filled with dry stationary phase powder, followed by the addition of mobile phase, which is flushed through the column until it is completely wet, and from ...
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]
This problem is classically addressed by the use of carrier ions. Thus, carrier addition involves the addition of a known mass of stable ion to radionuclide-containing sample solution. The carrier is of the identical element but is non-radioactive. The carrier and the radionuclide of interest have identical chemical properties.
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 ...
The first instrumental analysis was flame emissive spectrometry developed by Robert Bunsen and Gustav Kirchhoff who discovered rubidium (Rb) and caesium (Cs) in 1860. [4] Most of the major developments in analytical chemistry took place after 1900. During this period, instrumental analysis became progressively dominant in the field.
A Büchner funnel is a piece of laboratory equipment used in filtration. [1] It is traditionally made of porcelain , but glass and plastic funnels are also available. On top of the funnel-shaped part there is a cylinder with a fritted glass disc/perforated plate separating it from the funnel.
Diagram which depicts the basics of flow injection analysis. A sample is injected into a flowing carrier solution stream that is forced by a peristaltic pump. The injection of the sample is done under controlled dispersion in known volumes. The carrier solution and sample then meet at mixing points with reagents and react.