Technique for thermal desorption analyses of thermo labile volatile compounds
AssigneeThe United States of America as represented by the Secretary of Agriculture
InventorsHans T. Alborn, Steven D. Willms
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Abstract
Herein is described an apparatus for adaptation to existing GC/MS systems, utilizing a splitless injector as the desorption oven with a liquid CO2 cooled low thermal mass cryo trap that eliminates the need for flash heating of volatile compounds.
Claims2
An apparatus for the analysis of volatile organic compounds in a gas chromatogram thermal desorption system comprising a cooling trap directly attached to a split/splitless injector 1 and means of transferring desorbed compounds from injector to the top part of a chromatographic column located inside said trap, wherein said trap is characterized by low thermal mass, heat transfer from injector/desorption oven and a restrictor portion in the liquid cooled delivery segment of the trap that forces a pressure drop and cooling to occur at the end of the restrictor located at the bottom of the cryo trap.
A method for the analysis of volatile organic compounds in a thermal desorption system comprising a sampling and on column concentration of a gaseous sample in a temperature gradient cooling trap where heat exchange with chromatography oven eliminates the need of additional heating of said trap, characterized by low thermal mass, heat transfer from desorption system and a restrictor portion in the liquid cooled delivery segment of the trap that forces a pressure drop and cooling to occur at the end of the restrictor at the bottom of the trap.
Dependencies are inferred from the claim text.