Definition chromatografisches Verfahren, bei dem die mobile Phase gasförmig ist Reference E DIN 51405:2000: Prüfung von Mineral-Kohlenwasserstoffen, verwandten Flüssigkeiten und Lösemitteln für Lacke und Anstrichstoffe – Gaschromatographische Analyse – Allgemeine Arbeitsgrundlagen, S. 2
Definition separation technique in which the mobile phase is a gas Reference IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8 http://goldbook.iupac.org/G02578.html Last update: 2009-09-07; version: 2.1.5 [17.11.2009]
Comment Gas chromatography is always carried out in a column. It is a common type of chromatography used in organic chemistry for separating and analysing compounds that can be vaporised without decompositionIn gas chromatography the distinction between gas-liquid and gas-solid may be obscure because liquids are used to modify solid stationary phases, and because the solid supports for liquid stationary phases affect the chromatographic process. For classification by the phases used, the term relating to the predominant effect should be chosen.See also:- gas chromatography/mass spectroscopy (related) [ IATE:1295813 ]- gas chromatographic separation (related) [ IATE:1094399 ]- gas-liquid chromatography (narrower) [ IATE:1479581 ]- gas-solid chromatography (narrower) [ IATE:1717974 ]
Definition gas chromatography using a capillary column instead of a packed column Reference Based on: The Chemistry Hypermedia Project. Gas Chromatography Columns, http://www.files.chem.vt.edu/chem-ed/sep/gc/gc-col.html [31.8.2009]
Definition gas chromatography method associated with a detector which uses a radioactive beta emitter (electrons) to ionise some of the carrier gas and produce a current between a biased pair of electrodes, so that when organic molecules that contain electronegative functional groups, such as halogens, phosphorous, and nitro groups pass by the detector, they capture some of the electrons and reduce the current measured between the electrodes Reference COM-Terminology Coordination, based on:Shimadzu GC-8A with ECD Detector: Gas Chromatography. University of Nebraska-Lincoln. Department of Chemistry, http://www.chem.unl.edu/uic/gc-ecd.shtml [17.3.2014] & Brian M. Tissue. Electron Capture Detectors(ECD). ON-LINE EDUCATIONAL HYPERMEDIA, http://elchem.kaist.ac.kr/vt/chem-ed/sep/gc/detector/ecd.htm [17.3.2014]
Definition technique utilisée pour détecter des traces de composés chimiques dans un échantillon (et notamment pour analyser des composés halogénés) et qui associe la chromatographie en phase gazeuse avec un dispositif qui permet de détecter les atomes et les molécules d'un gaz à travers l'attachement des électrons par ionisation Reference COM-FR, d'après diverses sources.
Comment 'Retention time' is one of the most important chromatographic features for analytical chemists since it is the key parameter to separate, identify and quantify compounds of interest from complex mixtures. Although detectors with higher-dimensional signals ease the identification of many components, there are demanding requirements on the retention time, particularly when high-throughput methods are considered. In addition to this, gas chromatographic elution shows significant run-to-run variations due to fluctuations in temperature and pressure, column degradation or matrix effects. In this sense, different approaches have been developed to minimise those variations: the introduction of electronic pneumatic control (EPC) systems, which allow a very efficient control of the flow of the carrier gas, the use of peak alignment algorithms to treat the chromatograms, or the use of retention-time locking (RTL).
Definition Die Gaschromatographie eignet sich zur Bestimmung aller gasförmigen o. unzersetzt verdampfbaren Stoffe, also im wesentlichen von organischen Verbindungen. Eine Probe des zu untersuchenden Stoffgemisches wird in einen Trägergasstrom gebracht und durchströmt eine Trennsäule oder -kapillare mit einer speziellen Füllung bzw. Beschichtung. Stoffabhängige Wechselwirkungen in der Säule bewirken, daß die einzelnen Verbindungen unterschiedlich lange zurückgehalten werden und am Ende der Säule zeitlich getrennt austreten. Zur Detektion der austretenden Komponenten stehen verschiedene Techniken zur Verfügung. Mit einem nachgeschalteten Massenspektrometer lassen sich gleichzeitig Aussagen über Art und Menge der jeweiligen Substanz machen (Identifizierung und Quantifizierung). Dazu werden die austretenden Teilchen ionisiert und die gebildeten Molekülionen, die zum Teil zerfallen, entsprechend ihrem Verhältnis Masse/Ladung in einem Magnetfeld aufgetrennt. Das Muster der auftretenden Fragmente kann einem bestimmten Stoff zugeordnet werden. (Quelle s.o.) Reference ---
Definition two techniques that are combined to form a single method of analyzing mixtures of chemicals Reference George Mason University. Gas Chromatography-Mass Spectroscopy. Background http://www.gmu.edu/departments/SRIF/tutorial/gcd/gc-ms2.htm [17.11.2009]
Comment Gas chromatography ( IATE:1350135 ) separates the components of a mixture and mass spectroscopy ( IATE:1364881 ) characterizes each of the components individually. By combining the two techniques, an analytical chemist can both qualitatively and quantitatively evaluate a solution containing a number of chemicals.
Definition analytical technique coupling gas chromatography1 to tandem mass spectrometry21 gas chromatography [ IATE:1350135 ]2 tandem mass spectrometry [ IATE:157399 ] Reference COM-Terminology Coordination, based on:Renata Raina and Patricia Hall. Comparison of Gas Chromatography-Mass Spectrometry and Gas Chromatography-Tandem Mass Spectrometry with Electron Ionization and Negative-Ion Chemical Ionization for Analyses of Pesticides at Trace Levels in Atmospheric Samplesy. Anal Chem Insights 2008; 3: 111-125, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2701172/ [5.3.2014]
Definition Art der Flüssigchromatografie, bei der man sehr kleine Teilchen und einen relativ hohen Eingangsdruck verwendet Reference Engelhardt H., Rohrschneider L. (Bearbeiter), "Deutsche chromatographische Grundbegriffe zur IUPAC-Nomenklatur", Gesellschaft Deutscher Chemiker, Fachgruppe Analytische Chemie, Arbeitskreis Chromatographie, ca. 1999, S. 6, http://www.uni-saarland.de/fak8/huber/pdf/CHROBEGR97.pdf (28.07.2010)
Definition a variation of liquid chromatography that utilises very small particles and a relatively high inlet pressure to increase the efficiency of the separation Reference Based on: Rautiu & Tissue, Gloss. of Selected Terms, 1999, ICON & IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8 http://goldbook.iupac.org/L03578.html [8.9.2009]
Definition in this chromatographic technique, the packing is nonpolar and the solvent is polar with respect to the sample. Retention is the result of the interaction of the nonpolar components of the solutes and the nonpolar stationary phase. Reference Iowa State University, Office of Biotechnology http://www.protein.iastate.edu/hplc.html [7.10.2009]