Multiplexed electronically programmable multimode ionization detector for chromatography

Patent · Sat Dec 31 23:00:00 EST 1988

OSTI ID:867168

Wise, Marcus B ^[1]; Buchanan, Michelle V ^[2]

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1. Kingston, TN
2. Knoxville, TN

Method and apparatus for detecting and differentiating organic compounds based on their electron affinity. An electron capture detector cell (ECD) is operated in a plurality of multiplexed electroncially programmable operating modes to alter the detector response during a single sampling cycle to acquire multiple simultaneous chromatograms corresponding to each of the different operating modes. The cell is held at a constant subatmospheric pressure while the electron collection bias voltage applied to the cell is modulated electronically to allow acquisition of multiple chromatograms for a single sample elution from a chromatograph representing three distinctly different response modes. A system is provided which automatically controls the programmed application of bias pulses at different intervals and/or amplitudes to switch the detector from an ionization mode to the electron capture mode and various degrees therebetween to provide an improved means of tuning an ECD for multimode detection and improved specificity.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4879472
• OSTI ID: 867168
• Country of Publication: United States
• Language: English

Related Subjects

/250/
acquire
acquisition
affinity
allow
alter
amplitudes
apparatus
application
applied
atmospheric pressure
automatically
automatically control
based
bias
bias voltage
capture
capture detector
cell
chromatograms
chromatograph
chromatography
collection
compounds
compounds based
constant
controls
corresponding
cycle
degrees
detecting
detection
detector
detector cell
differentiating
differentiating organic
distinctly
ecd
electron
electron affinity
electron capture
electroncially
electronically
elution
held
improved
intervals
ionization
ionization detector
ionization mode
means
method
mode
modes
modulated
modulated electron
modulated electronic
multimode
multiple
multiplexed
operated
operating
operating mode
operating modes
organic
organic compound
organic compounds
plurality
pressure
programmable
programmed
provide
provided
pulses
representing
response
sample
sampling
simultaneous
single
specificity
subatmospheric
subatmospheric pressure
switch
therebetween
tuning
various
voltage
voltage applied