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Title: Method for detection of extremely low concentration

Abstract

An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and CO.sub.2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica--or other metal--aerogel material which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury that subsequently pass through a detection chamber which includes a detector cell, such as quartz, that is illuminated with a 254 nm ultra-violet (UV) mercury discharge lamp which generates the exact mercury absorption bands that are used to detect the liberated mercury atoms. Atomic mercury strongly absorbs 254 nm energy is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter the atomic mercury is trapped for example, in a silicon-aerogel trap.

Inventors:
 [1];  [2]
  1. (Livermore, CA)
  2. (Bethal Island, CA)
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
874199
Patent Number(s):
6338824
Assignee:
The Regents of the University of California (Oakland, CA) LLNL
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; detection; extremely; concentration; ultratrace; detector; hand-held; gas; chromatography; sensitivity; example; emissions; generated; production; weapons; biological; compounds; drugs; etc; insensitive; water; air; helium; argon; oxygen; cosub2; basically; composed; capillary; gc; insulated; heated; redox-chamber; chamber; vapor; trap; phase; redox; reactions; spectral; absorption; mercury; chromatograph; initially; separates; percolate; bed; mercuric; oxide; hgo; silica-or; metal-aerogel; material; insulator; easily; oxidized; liberate; atomic; subsequently; pass; cell; quartz; illuminated; 254; nm; ultra-violet; discharge; lamp; generates; exact; bands; detect; liberated; atoms; strongly; absorbs; energy; specific; signal; reducing; eluting; whereafter; trapped; silicon-aerogel; mercury vapor; emissions generated; /422/73/436/

Citation Formats

Andresen, Brian D., and Miller, Fred S. Method for detection of extremely low concentration. United States: N. p., 2002. Web.
Andresen, Brian D., & Miller, Fred S. Method for detection of extremely low concentration. United States.
Andresen, Brian D., and Miller, Fred S. Tue . "Method for detection of extremely low concentration". United States. https://www.osti.gov/servlets/purl/874199.
@article{osti_874199,
title = {Method for detection of extremely low concentration},
author = {Andresen, Brian D. and Miller, Fred S.},
abstractNote = {An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and CO.sub.2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica--or other metal--aerogel material which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury that subsequently pass through a detection chamber which includes a detector cell, such as quartz, that is illuminated with a 254 nm ultra-violet (UV) mercury discharge lamp which generates the exact mercury absorption bands that are used to detect the liberated mercury atoms. Atomic mercury strongly absorbs 254 nm energy is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter the atomic mercury is trapped for example, in a silicon-aerogel trap.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2002},
month = {1}
}

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