Refractive index and absorption detector for liquid chromatography based on Fabry-Perot interferometry

Patent · Tue Jun 19 00:00:00 EDT 1984

OSTI ID:865055

Yeung, Edward S ^[1]; Woodruff, Steven D ^[1]

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1. Ames, IA

A refractive index and absorption detector for liquid chromatography. It is based in part on a Fabry-Perot interferometer and is used for the improved detection of refractive index and absorption. It includes a Fabry-Perot interferometer having a normally fixed first partially reflecting mirror and a movable second partially reflecting mirror. A chromatographic flow-cell is positioned between the mirrors along the optical axis of a monochromatic laser beam passing through the interferometer. A means for deriving information about the interference fringes coming out of the interferometer is used with a mini-computer to compute the refractive index of the specimen injected into the flow cell. The minicomputer continuously scans the interferometer for continuous refractive index readings and outputs the continuous results of the scans on a chart recorder. The absorption of the specimen can concurrently be scanned by including a second optical path for an excitation laser which will not interfere with the first laser, but will affect the specimen so that absorption properties can be detected. By first scanning for the refractive index of the specimen, and then immediately adding the excitation laser and subsequently scanning for the refractive index again, the absorption of the specimen can be computed and recorded.

• Research Organization: Ames Laboratory (AMES), Ames, IA; Iowa State Univ., Ames, IA (United States)
• DOE Contract Number: W-7405-ENG-82
• Assignee: Iowa State University Research Foundation, Inc. (Ames, IA)
• Patent Number(s): US 4455089
• Application Number: 06/460,467
• OSTI ID: 865055
• Country of Publication: United States
• Language: English

Related Subjects

refractive
index
absorption
detector
liquid
chromatography
based
fabry-perot
interferometry
interferometer
improved
detection
normally
fixed
partially
reflecting
mirror
movable
chromatographic
flow-cell
positioned
mirrors
optical
axis
monochromatic
laser
beam
passing
means
deriving
information
interference
fringes
coming
mini-computer
compute
specimen
injected
flow
cell
minicomputer
continuously
scans
continuous
readings
outputs
results
chart
recorder
concurrently
scanned
including
path
excitation
interfere
affect
properties
detected
scanning
immediately
adding
subsequently
computed
recorded
liquid chromatograph
excitation laser
fabry-perot interferometer
reflecting mirror
optical axis
beam passing
laser beam
optical path
refractive index
flow cell
liquid chromatography
absorption detector
absorption properties
interference fringes
interference fringe
deriving information
fabry-perot interferometry
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