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 an alyse the diffusion coefficients of species in mixture. We present here an evaluation of this method. Various experimental tests demonstrates that thi s method is robust against experimental parameters like relaxation delay, g radients duration or pulse flip angle. Concerning the diffusion delay, it h as to be kept as short as possible because convection can appear during thi s delay. We show that the rotation of the sample permits to minimize convec tion effect. Moreover, we propose various gradient sampling strategies and show that they are equivalent fur a model case.