Continuous air monitoring apparatus and method
AssigneeCMS Research Corporation
InventorsGary D. Sides, Marion H. Cates
Life of this patent
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Abstract
A continuous air monitoring apparatus utilizes a solid sorbent preconcentrator to concentrate airborne sorbent compounds for gas chromatographic analysis. Direct connection between the preconcentrator and gas chromatographic column allows direct desorption of the compounds into the column with minimal dead space. Temperature control on the column allows sharp chromatographic peaks to be attained with cryogenic focussing.
Claims20
Apparatus for use in gas chromatography comprising:
- (a) a gas chromotographic column;
- (b) a solid sorbent preconcentrator tube in communication with said gas chromatographic column;
- (c) means for selectively introducing an airstream to be sampled or a carrier gas to said solid sorbent preconcentrator tube at ambient temperatures;
- (d) means for selectively venting said carrier gas, intermediate said preconcentrator tube, and said gas chromatographic column;
- and
- (e) means for backflushing said gas chromatographic column with a gas.
A method of detection of selected airborne sorbates, such as chemical warfare agents and other volatile compounds, in ambient air utilizing remote monitors including solid sorbent collectors and gas chromatographic columns comprising the steps of:
- (a) drawing ambient air through said solid sorbent collectors for a period of time to concentrate said sorbates into a detectable quantity;
- (b) purging said ambient air from said solid sorbent collectors and said gas chromatographic column;
- (c) desorbing said sorbates from said solid sorbent collectors into a carrier gas for direct transport to said gas chromatographic column;
- (d) separating the selected sorbates from interference using gas chromatography;
- (e) detecting said selected sorbates using flame photometric detection;
- and
- (f) iterative repetition of the above steps on a defined schedule with the flow of said carrier gas through said solid sorbent collector and said gas chromatographic column being discontinuous to permit sampling of the ambient air.
Dependencies are inferred from the claim text.