Liquid chromatography/Fourier transform IR spectrometry interface flow cell

Patent · Wed Jan 01 00:00:00 EST 1986

OSTI ID:866031

Johnson, Charles C ^[1]; Taylor, Larry T ^[2]

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1. Fairfield, OH
2. Blacksburg, VA

A zero dead volume (ZDV) microbore high performance liquid chromatography (.mu.HPLC)/Fourier transform infrared (FTIR) interface flow cell includes an IR transparent crystal having a small diameter bore therein through which a sample liquid is passed. The interface flow cell further includes a metal holder in combination with a pair of inner, compressible seals for directly coupling the thus configured spectrometric flow cell to the outlet of a .mu.HPLC column end fitting to minimize the transfer volume of the effluents exiting the .mu.HPLC column which exhibit excellent flow characteristics due to the essentially unencumbered, open-flow design. The IR beam passes transverse to the sample flow through the circular bore within the IR transparent crystal, which is preferably comprised of potassium bromide (KBr) or calcium fluoride (CaF.sub.2), so as to minimize interference patterns and vignetting encountered in conventional parallel-plate IR cells. The long IR beam pathlength and lensing effect of the circular cross-section of the sample volume in combination with the refractive index differences between the solvent and the transparent crystal serve to focus the IR beam in enhancing sample detection sensitivity by an order of magnitude.

• Research Organization: Virginia Tech Intellectual Properties, Inc. (Blacksburg, VA)
• DOE Contract Number: FG22-81PC40799
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 4618769
• OSTI ID: 866031
• Country of Publication: United States
• Language: English

Related Subjects

liquid
chromatography
fourier
transform
spectrometry
interface
flow
cell
zero
dead
volume
zdv
microbore
performance
hplc
infrared
ftir
transparent
crystal
diameter
bore
therein
sample
passed
metal
holder
combination
pair
inner
compressible
seals
directly
coupling
configured
spectrometric
outlet
column
fitting
minimize
transfer
effluents
exiting
exhibit
excellent
characteristics
due
essentially
unencumbered
open-flow
design
beam
passes
transverse
circular
preferably
comprised
potassium
bromide
kbr
calcium
fluoride
caf
interference
patterns
vignetting
encountered
conventional
parallel-plate
cells
pathlength
lensing
effect
cross-section
refractive
index
differences
solvent
serve
focus
enhancing
detection
sensitivity
magnitude
performance liquid
detection sensitivity
liquid chromatograph
preferably comprised
interference pattern
beam passes
dead volume
refractive index
flow cell
fourier transform
liquid chromatography
beam path
calcium fluoride
sample detection
zero dead
circular bore
sample volume
transparent crystal
transform infrared
interference patterns
bore therein
sample flow
spectrometry interface
circular cross-section
flow characteristics
hplc column
interface flow
preferably comprise
directly coupling
/250/356/