We have done a lot of this type of work using a standard curve based on commercial
polystyrene (
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/polystyrene )
samples with molecular weights of 1,650, 60,450, 956,000, and 3,050,000 Da.
This was inspired by on the work of Weibin Li, et al, " Application of 1 H DOSY
for Facile Measurement of Polymer Molecular Weights" from 2012 ( Macromolecules 2012 , 45 , 24 , 9595-9603,
https://doi.org/10.1021/ma301666x ).
Our results compare very favorably with those from GPC and, in fact, one of our
scientists has decided not to spend the money to repair his broken GPC because
he trusts the NMR results so well.
Of course, care must be taken to avoid convection and ensure proper dilution
to avoid aggregation. And, one must run replicates, especially for the curve.
You can probably find many references using variations of this method, including
our own.
Gary Strahan, Ph.D.
Magnetic Resonance Facility - Core Technologies
Eastern Regional Research Center, ARS, USDA
600 E. Mermaid Lane, Wyndmoor, PA 19038
gary.strahan_at_usda.gov
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