Ultratrace detector for hand-held gas chromatography
- Livermore, CA
- Bethal Island, CA
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 C0.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.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA
- DOE Contract Number:
- W-7405-ENG-48
- Assignee:
- Regents of University of California (Oakland, CA)
- Patent Number(s):
- US 5980832
- OSTI ID:
- 872647
- Country of Publication:
- United States
- Language:
- English
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254
absorbs
absorption
absorption band
absorption bands
aerogel material
air
argon
atomic
atoms
bands
basically
basically composed
bed
biological
biological compounds
c0
capillary
capillary gas
capillary gc
cell
chamber
chromatograph
chromatography
composed
compounds
detect
detection
detector
detector cell
discharge
discharge lamp
drugs
easily
eluting
emissions
emissions generated
energy
etc
exact
example
gas
gas chromatograph
gas chromatography
gas phase
gc
generated
generates
hand-held
hand-held gas
heated
helium
hgo
illuminated
initially
insensitive
insulated
insulator
lamp
liberate
liberated
material
mercuric
mercury
mercury vapor
metal--aerogel
nm
oxide
oxidized
oxygen
pass
percolate
phase
production
quartz
reactions
redox
redox reaction
redox-chamber
reducing
sensitivity
separates
signal
silica--or
silicon-aerogel
specific
spectral
strongly
subsequently
trap
trapped
ultra-violet
ultratrace
ultratrace detector
vapor
vapor trap
water
weapons
whereafter