Concentration Gradient Detection by Near-Infrared Diode Laser Interferometry

Abstract

Concentration gradient detection is performed with a diode laser system which probes the associated refractive index gradient (RIG). The detector has excellent potential for both High Performance Liquid Chromatography (HPLC) and Flow Injection Analysis (FIA). The RIG detector measured 280 picograms (3 x rms) of injected polystyrene following size-exclusion chromatography (SEC). A version incorporating a position sensitive detector in lieu of interferomatic measurement allows laser beam deflection angles of less than 2.4 microradians to be measured. The system performance as a universal detector for HPLC is contrasted with UV-Vis detection. The device is clearly superior to UV-Vis detection of species that are not highly absorbing. RIG sensitivity to solute peak broadening also promises rapid polymer characterization potential with a FIA scheme.

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Document Details

Document Type
Technical Report
Publication Date
May 23, 1988
Accession Number
ADA196197

Entities

People

  • Darrell O. Hancock

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Advanced Electronics
  • Engineered Resilient Systems
  • Sensors

DTIC Thesaurus Topics

  • Chemical Analysis
  • Chemistry
  • Detection
  • Detectors
  • Dielectric Polymers
  • Interferometry
  • Laser Beams
  • Laser Diodes
  • Lasers
  • Light Sources
  • Liquid Chromatography
  • Materials
  • Measurement
  • Optics
  • Physical Properties
  • Polymers
  • Refractive Index

Fields of Study

  • Physics

Readers

  • Agricultural Chemistry/Soil Science
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers