Patent ID: 8117896
Filing Date: 2012-02-21
Classification: G01N

Abstract:
1. A gas chromatograph comprising: a preconcentrator configured to receive a vapor and comprising a hollow enclosure defined by a wall, wherein the inner surface of the wall is coated with a sorbent material, and wherein the sorbent material absorbs a target chemical from the vapor at a first temperature and desorbs the target chemical at a second temperature; and a chromatograph column coupled to the preconcentrator and configured to receive an outflow of the preconcentrator, wherein the temperature within the hollow enclosure is selectively cycled to concentrate the target chemical in the outflow for at least a portion of the temperature cycle, wherein the hollow enclosure is heated by passing an electrical current through the wall, and wherein temperature within the hollow enclosure is controlled by cycling the electrical current that heats the hollow enclosure.