Investigation of the diffusion measurement using PFG and test of robustness against experimental conditions and parameters

The DOSY experiment, based on pulsed-field gradient (PFG) NMR, is used to analyse the diffusion coefficients of species in mixture. We present here an evaluation of this method. Various experimental tests demonstrates that this method is robust against experimental parameters like relaxation delay, gradients duration or pulse flip angle. Concerning the diffusion delay, it has to be kept as short as possible because convection can appear during this delay. We show that the rotation of the sample permits to minimize convection effect. Moreover, we propose various gradient sampling strategies and show that they are equivalent for a model case