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The target analytes are extracted by mixing the sample with water and purge with inert gas (e.g. Nitrogen gas) into an airtight chamber, this is known as purging or sparging. The volatile compounds move into the headspace above the water and are drawn along a pressure gradient (caused by the introduction of the purge gas) out of the chamber.
Gas chromatography-mass spectrometry is a widely used analytical technique for the detection of volatile compounds. Ionization techniques most frequently used in forensic toxicology include electron ionization (EI) or chemical ionization (CI), with EI being preferred in forensic analysis due to its detailed mass spectra and its large library of ...
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 (GC) performs the same function as liquid chromatography, but it is used for volatile mixtures. In forensic chemistry, the most common GC instruments use mass spectrometry as their detector. [1] GC-MS can be used in investigations of arson, poisoning, and explosions to determine exactly what was used.
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 ...
Silylations are core methods for production of organosilicon chemistry. Silanization, while similar to silylation, usually refers to attachment of silyl groups to solids. [1] Silyl groups are commonly used for: alcohol protection, enolate trapping, gas chromatography, electron-impact mass spectrometry (EI-MS), and coordinating with metal complexes.
The coefficient of determination (R 2) for this plot is 0.9985. In the calibration curve that uses the internal standard, the y-axis is the ratio of the nickel signal to the yttrium signal. This ratio is unaffected by uncertainty in the nickel measurements, as it should affect the yttrium measurements in the same way.
In chemistry, an alcohol (from Arabic al-kuḥl 'the kohl'), [2] is a type of organic compound that carries at least one hydroxyl (−OH) functional group bound to a saturated carbon atom. [ 3 ] [ 4 ] Alcohols range from the simple, like methanol and ethanol , to complex, like sugars and cholesterol .