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

A reliable method of sample introduction is presented for online gas chromatography with a special application to in situ field portable atmospheric sampling instruments. A traditional multi-port valve is replaced with a valveless sample introduction interface that offers the advantage of long-term reliability and stable sample transfer efficiency. An engineering design model is presented and tested that allows customizing this pressure-switching-based device for other applications. Flow model accuracy is within measurement accuracy (1%) when parameters are tuned for an ambient-pressure 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 that the new interface has approximately 3 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 typically less than 2% week -1 response trending and a zero failure rate during field deployments ranging up to 4 weeks of continuous sampling. Extension of the valveless interface to dual collection cells is presented with less than 3% cell-to-cell carryover.
 [1] ;  [2] ;  [3] ;  [3] ;  [3] ;  [1]
  1. Aerosol Dynamics, Inc., Berkeley, CA (United States)
  2. Aerosol Dynamics, Inc., Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
  3. Univ. of California, Berkeley, CA (United States)
Publication Date:
Grant/Contract Number:
FG02-05ER 86235
Published Article
Journal Name:
Atmospheric Measurement Techniques (Online)
Additional Journal Information:
Journal Name: Atmospheric Measurement Techniques (Online); Journal Volume: 7; Journal Issue: 12; Related Information: CHORUS Timestamp: 2014-12-12 07:48:23; Journal ID: ISSN 1867-8548
European Geosciences Union
Sponsoring Org:
USDOE; National Science Foundation (NSF)
Country of Publication:
OSTI Identifier: