Summary:
Diffusion-ordered spectroscopy (DOSY) can be used both to distinguish the signals of different species in solution, and to measure their diffusion coefficients, provided that their signals are resolved in the chemical shift dimension. The accuracy of the experiment can be however be degraded by phase errors that vary with pulsed field gradient strength, and degraded or even or even ruined altogether by convection. Using a combination of x- and y-PFGs (pulsed-field gradients) can reduce the impact both of gradient-dependent phase errors and of convection. This pulse sequence requires special hardware (NMR probe and PFG amplifier) to support the use of triaxial pulsed field gradients. The pulse sequence code is similar to the standard Oneshot experiment of VnmrJ 4.0, extended to allow diffusion encoding along any axis. An example data set is also provided to help the correct setting of parameters.
Downloads:
Varian / Agilent
Pulse sequence code: .c file. (copy to ~/vnmrsys/psglib/.)
Macro files: .zip file. (extract and copy to ~/vnmrsys/maclib/.)
Example data set: .zip file. (extract and copy .fid directories to any data directory)
Bruker
Not available from us
Reference:
Improving accuracy in DOSY and diffusion measurements using triaxial field gradients
Kiraly, P.; Swan, I.; Nilsson, M.; Morris, G.A.
J. Magn. Reson. 2016, 270, 24-30