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The mass spectrometry process normally requires a very pure sample while gas chromatography using a traditional detector (e.g. Flame ionization detector) cannot differentiate between multiple molecules that happen to take the same amount of time to travel through the column (i.e. have the same retention time), which results in two or more ...
Although thousand different substances can be determined in a single gas chromatography–mass spectrometry or liquid chromatography–mass spectrometry experiment, due to the low concentration of analytes, practical measurements (see selective ion monitoring) are limited to a smaller number (10-20) of analytes.
Clinical consideration and professional judgment should be applied to any drug of abuse test result, in evaluating a preliminary positive result. To obtain a confirmed analytical result, a more specific alternate chemical method is needed. Gas chromatography/mass spectrometry (GC/MS) is the recommended confirmatory method."
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.
Both, the first mass analyzer and the collision cell are continuously exposed to ions from the source, in a time independent manner. [4] It is once the ions move into the third mass analyzer that time dependence becomes a factor. [4] The first quadrupole mass filter, Q1, is the primary m/z selector after the sample leaves the ionization source.
Agilent serves analytical laboratories and the clinical and routine diagnostics markets with a full suite of technology platforms. These include: automation, bioreagents, FISH probes, gas and liquid chromatography, immunohistochemistry, informatics, mass spectrometry, microarrays, spectroscopy, target enrichment, and vacuum technologies. [6]
Atmospheric pressure chemical ionization chamber cross section. Atmospheric pressure chemical ionization (APCI) is an ionization method used in mass spectrometry which utilizes gas-phase ion-molecule reactions at atmospheric pressure (10 5 Pa), [1] [2] commonly coupled with high-performance liquid chromatography (HPLC). [3]
Chiral chromatographic assay is the first step in any study pertaining to enantioselective synthesis or separation. This includes the use of techniques viz. gas chromatography (GC), high performance liquid chromatography (HPLC), chiral supercritical fluid chromatography (SFC), capillary electrophoresis (CE) [35] and thin-layer chromatography (TLC).