DOSY

DOSY (Diffusion Ordered SpectroscopY)

From the paper:

An Improved Diffusion-Ordered Spectroscopy Experiment Incorporating Bipolar-Gradient Pulses From Bruker

pk.stebpgp1s19: Stimulated Echo experiment using bipolar gradients

and WATERGATE acquired in 2D mode. d20 = Diffusion time, little delta= gradient duration

Sample: 13C, 15N-labeled Ubiquitin + 2% glycerol-d8 at 298K

Data Analysis: DOSY type experiments are used to determine the diffusion coefficient of the species in the sample. Curve fitting is used to calculate Diffusion Coefficient using the TopSpin analysis tool.

Diffusion Coefficient of a spherical molecule is calculated by the Stokes Einstein equation:

where k=Boltzmann constant, T=temperature, r= hydrodynamic radius.

The signal intensity measured in the pulsed field gradient NMR experiment is given by the following equation:

References:

1. D. H. Wu, A. Chen and C. S. Johnson, " An Improved Diffusion-Ordered Spectroscopy Experiment Incorporating Bipolar-Gradient Pulses". JMR, A 115, 123 (1995).

2.