Search results
Results from the WOW.Com Content Network
Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, or separating the different components of a mixture. [ 1 ]
Gas chromatography–mass spectrometry (GC–MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. [1] Applications of GC–MS include drug detection, fire investigation, environmental analysis, explosives investigation, food and flavor analysis ...
One of the most widely used methods for headspace analysis is described by the United States Environmental Protection Agency (USEPA). Originally developed by the R.S. Kerr USEPA Laboratory in Ada, Oklahoma as a "high quality, defendable, and documented way to measure" methane, ethane, and ethene, [7] [8] RSKSOP-175 is a standard operating procedure (SOP) and an unofficial method employed by ...
Pyrolysis–gas chromatography–mass spectrometry is a method of chemical analysis in which the sample is heated to decomposition to produce smaller molecules that are separated by gas chromatography and detected using mass spectrometry. Pyrolysis is the thermal decomposition of materials in an inert atmosphere or a vacuum.
Nucleotide bonds showing AT and GC pairs. Arrows point to the hydrogen bonds.. In molecular biology and genetics, GC-content (or guanine-cytosine content) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). [1]
In chemistry, functionality is the presence of functional groups in a molecule. A monofunctional molecule possesses one functional group, a bifunctional (or difunctional) two, a trifunctional three, and so forth. In organic chemistry (and other fields of chemistry), a molecule's functionality has a decisive influence on its reactivity.
Gas chromatography–vacuum ultraviolet spectroscopy (GC-VUV) is a universal detection technique for gas chromatography. [1] VUV detection provides both qualitative and quantitative spectral information for most gas phase compounds. GC-VUV spectral data is three-dimensional (time, absorbance, wavelength) and specific to chemical structure.
Analytical thermal desorption, known within the analytical chemistry community simply as "thermal desorption" (TD), is a technique that concentrates volatile organic compounds (VOCs) in gas streams prior to injection into a gas chromatograph (GC). It can be used to lower the detection limits of GC methods, and can improve chromatographic ...