Multiplexed electronically programmable multimode ionization detector for chromatography

Patent · Mon Nov 06 23:00:00 EST 1989

OSTI ID:6963161

Wise, M B; Buchanan, M V

This patent describes 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 electronically 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.

• Assignee: Dept. of Energy, Washington, DC
• Patent Number(s): A; US 4879472
• Application Number: PPN: US 7-196693A
• OSTI ID: 6963161
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
42 ENGINEERING
426000 -- Engineering-- Components
Electron Devices & Circuits-- (1990-)
440800 -- Miscellaneous Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
AUTOMATION
CAPTURE
CHROMATOGRAPHY
DATA ACQUISITION
ELECTRON CAPTURE
ELECTRONIC EQUIPMENT
EQUIPMENT
IONIZATION
MEASURING METHODS
MULTI-CHANNEL ANALYZERS
PULSE ANALYZERS
SAMPLING
SEPARATION PROCESSES