I have a student in our lab that is measuring T1 values and has run
across something interesting. He is using the standard inversion recovery
method and found, for example, that the first time he measured the T1 of
H2O from the residual solvent peak in D2O that it was about 20 sec. A few
days later, same sample, same temperature led to a result of 15 sec.
That's quite a difference and seems to be a general result for
all of the protons of interest in his samples. There appears to be no
great consistency in his numbers. These are not degassed samples.
I'm not very up on T1 measurements and the practical pitfalls that apply
so I thought I'd throw it out to the group.
Dr. Keith Brown
Department of Chemistry/
Saskatchewan Structural Sciences Center
University of Saskatchewan
Saskatoon, Saskatchewan
306-966-1725
http://chem4823.usask.ca/chem112/kbrown.html
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Received on Fri Dec 07 2012 - 06:15:02 MST