Rapid-scan EPR with triangular scans and fourier deconvolution to recover the slow-scan spectrum

J Magn Reson. 2005 Jul;175(1):44-51. doi: 10.1016/j.jmr.2005.03.013. Epub 2005 Apr 14.

Abstract

Direct-detected rapid-scan EPR signals were recorded using triangular field scan rates between 1.7 and 150 kG/s for deoxygenated samples of lithium phthalocyanine (LiPc) and Nycomed trityl-CD3. These scan rates are rapid relative to the reciprocals of the electron spin relaxation times and cause characteristic oscillations in the signals. Fourier deconvolution with an analytical function permitted recovery of lineshapes that are in good agreement with experimental slow-scan spectra. Unlike slow-scan EPR, direct detection rapid-scan EPR does not use phase sensitive detection and records the absorption signal directly instead of the first derivative of the absorption signal. The amplitude of the signal decreases approximately linearly with applied magnetic field gradient. Images of phantoms constructed from samples of LiPc and trityl-CD3 were reconstructed by filtered back-projection from data sets with a missing angle. The lineshapes in spectral slices from the image are in good agreement with slow-scan spectra and the spacing between sample tubes matches well with the known sample geometry.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Algorithms*
  • Electron Spin Resonance Spectroscopy / methods*
  • Ferric Compounds / analysis*
  • Ferric Compounds / chemistry
  • Fourier Analysis
  • Indoles / analysis*
  • Indoles / chemistry
  • Iron / analysis*
  • Iron / chemistry
  • Organometallic Compounds / analysis*
  • Organometallic Compounds / chemistry
  • Oxides / analysis*
  • Oxides / chemistry
  • Regression Analysis
  • Trityl Compounds / analysis*
  • Trityl Compounds / chemistry

Substances

  • Ferric Compounds
  • Indoles
  • Organometallic Compounds
  • Oxides
  • Sonazoid
  • Trityl Compounds
  • lithium phthalocyanine
  • Iron