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

Patent · Tue Jun 19 04:00:00 EDT 1984

OSTI ID:7148107

Yeung, E S; Woodruff, S D

A refractive index and absorption detector are disclosed 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. 10 figs.

• DOE Contract Number: W-7405-ENG-82
• Assignee: Iowa State Univ. Research Foundation, Inc., Ames, IA (United States)
• Patent Number(s): A; US 4455089
• Application Number: PPN: US 6-460467
• OSTI ID: 7148107
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
400105 -- Separation Procedures
ABSORPTION
CHROMATOGRAPHY
DESIGN
ELECTROMAGNETIC RADIATION
FABRY-PEROT INTERFEROMETER
FLUIDS
INTERFEROMETERS
LASER RADIATION
LIQUID COLUMN CHROMATOGRAPHY
LIQUIDS
MEASURING INSTRUMENTS
MONITORING
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
REFRACTIVE INDEX
SEPARATION PROCESSES
SORPTION