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

Media Info

• Features: Figures;
• Pagination: p. 26
• Serial:
  • Publication of: National Aeronautics and Space Administration
  • Publisher: National Aeronautics and Space Administration

Subject/Index Terms

• TRT Terms: Adsorption; Chemical concentration; Evaluation; Gas chromatography; Mathematical analysis; Methodology; Surfaces
• Uncontrolled Terms: Concentration; Surface area
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

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