Hi all,
Apologies if these topics have been covered; I've been having trouble with the search function.
We're looking at buying new 4 mm pencil rotors for our Varian T3 widebore solids probe and I wonder whether anyone has any comments on which vendor or what sort of setup is preferable in terms of long-term rotor stability. I've found that some of our rotors won't spin above 8 kHz after several months of usage and I'm not sure whether it depends on source of rotor. How have people's experience been with their original rotors vs rotors purchased from 3rd parties? Or is it necessary to continuously use long bottom inserts? Our samples are usually ground powders, nothing that should be tricky.
Also, does anyone have any thoughts about getting good baseline with DD2 data in 13C CPMAS experiments? On our VNMRS, spectra appear to have a flat baseline when processed in VnmrJ (rd=4, ad=4, ddrtc=8) but a hump when processed in Mnova or TopSpin, particularly for longer experiments (more than 1000 scans). I have tried to play with backwards linear prediction and removing the first point and so on but I can't get quite the same appearance.
I'll summarize comments if there is interest.
Thanks very much.
Robin
Robin Stein
NMR Facility Manager, Dept of Chemistry, McGill University
Room 35B, Otto Maass, 801 Sherbrooke St. West
Montreal, QC H3A 0B8
514-398-6219
robin.stein_at_mcgill.ca<mailto:robin.stein_at_mcgill.ca>
http://nmr.chem.mcgill.ca
https://twitter.com/mcgillnmr
Received on Thu Feb 02 2017 - 04:17:11 MST