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Title: Development of an automated high temperature valveless injection system for on-line gas chromatography

A reliable method of sample introduction is presented for on-line gas chromatography with a special application to in-situ field portable atmospheric sampling instruments. A traditional multi-port valve is replaced with a controlled pressure switching device that offers the advantage of long term reliability and stable sample transfer efficiency. An engineering design model is presented and tested that allows customizing the interface for other applications. Flow model accuracy is within measurement accuracy (1%) when parameters are tuned for an ambient detector and 15% accurate when applied to a vacuum based detector. Laboratory comparisons made between the two methods of sample introduction using a thermal desorption aerosol gas chromatograph (TAG) show approximately three times greater reproducibility maintained over the equivalent of a week of continuous sampling. Field performance results for two versions of the valveless interface used in the in-situ instrument demonstrate minimal trending and a zero failure rate during field deployments ranging up to four weeks of continuous sampling. Extension of the VLI to dual collection cells is presented with less than 3% cell-to-cell carry-over.
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Publication Date:
OSTI Identifier:
Grant/Contract Number:
FG02-05ER 86235
Published Article
Journal Name:
Atmospheric Measurement Techniques Discussions (Online)
Additional Journal Information:
Journal Name: Atmospheric Measurement Techniques Discussions (Online); Journal Volume: 7; Journal Issue: 7; Journal ID: ISSN 1867-8610
European Geosciences Union
Sponsoring Org:
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