Method and apparatus for concentrating a VOC sample

• Main Author: NEAL DAVID M
• Format: Patent
• Language: English
• Published: 18.11.2003
• Edition: 7
• Subjects: GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TESTING

A system for concentrating a volatile organic compound (VOC) sample uses in one embodiment a bypass line and a valve coupled thereto to regulate an amount of carrier gas flowing through a carrier gas line. A flow splitter fluidly couples the bypass line to the carrier gas line, and connects to the output of a cryofocuser. The valve opens at the onset of transferring the VOC sample from a concentrator trap such as a sorbent trap to the cryofocuser, thereby resulting in an increased amount of carrier gas flow between the concentrator trap and the cryofocuser for more efficient desorbing of the concentrator trap. The valve is closed when the focused VOC sample is flushed out of the cryofocuser for delivery to a gas chromatograph, preferably delivering the entire VOC sample to the GC.