Thanks for all the helpful responses. The information I got is that
CFCl3 ("Freon11") is still available, both Aldrich and ABCR (Germany)
list it on their websites - although it does not appear in the UK
(paper) edition of the Aldrich catalogue, hence my original query.
Several people helpfully suggested secondary standards which could be
used in place of CFCl3 if necessary (favourites were hexafluorobenzene,
trifluorotoluene, and CFBr3).
Several people pointed out that following the recent IUPAC
recommendations I should only need TMS and a properly set up
spectrometer. This is true, but occasionally I get customers who need
to run unlocked fluorine samples (in non-deuterated solvents) and still
want a good idea of what the chemical shift is. External reference
leads to susceptibility problems, so ....
Thanks, as ever, for all the help.
--
Alan.
Alan M Kenwright Phone +44-191-334-2095
Senior Research Officer (NMR)
Department of Chemistry
Durham University
Durham DH1 3LE UK
Received on Tue Nov 07 2006 - 10:41:51 MST