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

Patent · Tue Jun 19 00:00:00 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): US 4455089; A
• Application Number: PPN: US 6-460467
• OSTI ID: 7148107
• Resource Relation: Patent File Date: 24 Jan 1983
• Country of Publication: United States
• Language: English

Related Subjects

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