DYNAMIC TECHNIQUE FOR MEASURING ADSORPTION IN A GAS CHROMATOGRAPH

The adsorption characteristics of a compound can be obtained with the help of a gas chromatograph. However, when studying the adsorption of materials at low concentrations (less than 1 ppm) the standard technique requires several hours. A dynamic gas-chromatographic procedure, together with a mathematical analysis of the adsorption isotherm, allows relative surface areas and adsorptive powers for trace concentrations to be determined in a few minutes. The adsorbent (charcoal for instance) heated in vacuum until it is free of all adsorbed compounds, is packed in a gas-chromatograph column. The retention volume of the compound of interest is measured in a temperature-controllable chromatograph. An inert gas such as nitrogen is used as a carrier. This technique may be used to evaluate the relative surface areas of different adsorbates, expressed as a volume of adsorbent/gram of adsorbate, and to evaluate their relative adsorptive power.

  • Supplemental Notes:
    • This article appeared in a publication Analytical Techniques: A Compilation.
  • Corporate Authors:

    National Aeronautics and Space Administration

    400 Maryland Avenue, SW
    Washington, DC  United States  20546
  • Authors:
    • Deuel, C L
    • Hultgren, N W
    • Mobert, M L
  • Publication Date: 1975-1

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Filing Info

  • Accession Number: 00128516
  • Record Type: Publication
  • Report/Paper Numbers: NASA CR-115202
  • Files: TRIS
  • Created Date: Apr 21 1976 12:00AM