Development, simulation, and validation of NMR relaxation-based exchange measurements

J Chem Phys. 2009 Oct 28;131(16):164502. doi: 10.1063/1.3245866.

Abstract

Two-dimensional (2D) nuclear magnetic resonance correlation experiments have recently been proposed as a means for studying exchange in porous media. Most notable of these is the T(2)-T(2) relaxation exchange spectroscopy (REXSY) experiment. Unfortunately, quantifying exchange with this method requires a relatively long, three-dimensional acquisition. To reduce acquisition times, novel 2D methods for quantifying exchange were developed. For each method, model equations were derived (for an arbitrary N-pool system), tested via simulation studies, and validated via experimental studies in an aqueous urea model system. Results indicate that the novel methods outperform REXSY-in terms of uncertainty per unit time for the fitted exchange rate-for certain model systems. The relative merits of each method are discussed in the text.

Publication types

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

MeSH terms

  • Indicators and Reagents / chemistry
  • Magnetic Resonance Spectroscopy
  • Models, Chemical*
  • Protons
  • Urea / chemistry
  • Water / chemistry

Substances

  • Indicators and Reagents
  • Protons
  • Water
  • Urea