A Convenient Device for Removing Dissolved Oxygen from NMR Samples

  • Nagabhushanam Mandava


The presence of paramagnetic impurities, including molecular oxygen, in a sample causes line broadening in the high-resolution nuclear magnetic resonance (NMR) spectrum. Some of these paramagnetic impurities can sometimes be eliminated by adapting the conventional methods, such as filtering the sample solutions for insoluble impurities and shaking water-immiscible solutions with dilute hydrochloric acid for soluble impurities.1,2 The recommended procedures for removing dissolved oxygen from NMR samples involve vacuum distillation, out-gassing at the boiling point of the solution, or flushing with oxygen-free nitrogen. Multiple freeze-pump-thaw cycles, which exclude oxygen rigorously, are also in use. Removal of this dissolved impurity is particularly desirable when dealing with compounds such as olefins and aromatic hydrocarbons which tend to form charge-transfer complexes with oxygen. Recently, it was claimed that shaking the sample solution with 10% sodium thionate (Na2S2O4) solution eliminates oxygen, as was evidenced by considerable improvement in the resolution.3


Nuclear Magnetic Resonance Dilute Hydrochloric Acid Hypodermic Needle Paramagnetic Impurity Nuclear Magnetic Resonance Tube 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    L. M. Jackman and S. Sternhell, Applications of Nuclear Magnetic Resonance Spectroscopy in Organic Chemistry (Pergamon, Oxford, 1969), 2nd ed., p. 36.Google Scholar
  2. 2.
    F. A. Bovey, Nuclear Magnetic Resonance Spectroscopy ( Academic, New York, 1969 ), p. 45.Google Scholar
  3. 3.
    G. C. Brophy, O. N. Laing, and S. Sternhell, Chem. Ind. 22 (1968).Google Scholar
  4. 4.
    J. C. Metcalfe, A. S. V. Burgen, and O. Jardetzky, in Molecular Associations in Biology, edited by B. Pullman ( Academic, New York, 1968 ), p. 287.Google Scholar
  5. 5.
    J. J. M. Rowe, J. Hinton, and K. L. Rowe, Chem. Rev. 70, 1 (1970).CrossRefGoogle Scholar
  6. 6.
    F. A. L. Anet and A. J. R. Bourn, J. Amer. Chem. Soc. 87, 5250 (1965).CrossRefGoogle Scholar
  7. 7.
    N. Mandava and E. L. Goodell, J. Agr. Food Chem. 18, 172 (1970).CrossRefGoogle Scholar
  8. 8.
    S. Sternhell, Rev. Pure Appl. Chem. (Australia) 14, 15 (1984).Google Scholar

Copyright information

© Springer Science+Business Media New York 1974

Authors and Affiliations

  • Nagabhushanam Mandava
    • 1
  1. 1.Crops Research Division, Agricultural Research ServiceU. S. Department of AgricultureBeltsvilleUSA

Personalised recommendations