Accounting for Spin Relaxation in Quantitative Pulse Gradient Spin Echo NMR Mixture Analysis

Pulsed gradient spin−echo (PGSE) NMR is intrinsically nonquantitative. Because the experiment is echo-based, differences in the relaxation behavior of the nuclei among the components give rise to varied intensities and lead to nonquantitative spectra. A method is presented that restores resolved, quantitative spectra from mixtures by processing data from several PGSE NMR experiments with varied delay times. The approach incorporates a simple data acquisition scheme and leads to a computationally fast, linear least-squares analysis. It is anticipated the method will be of much interest for performing mixture analysis of polymer solutions and the characterization of surface-modified nanoparticulate dispersions.