AVIII 400 MHz – Probe Repair Date


The probe will be sent to Bruker’s shop on Monday, August 14th. The system will likely be unavailable during this repair. Turnaround from Bruker probe repairs range from 1-3 weeks. They have be notified of the critical nature of this automated system and will attempt to return the probe to us quickly and/or provide us with a back-up probe.

Thanks for your patience with this hardware issue, and thanks for being more careful with sample handling. The last time this probe needed to be sent to Bruker’s shop was in 2012, so let’s try for another long run without major issues!

Email from 7.14.2017

As most of you are aware – we’ve been seeing peak doubling on the AVII 400 MHz for all X-nuclei experiments (13C, 19F, 31P, 11B, etc.).  Data for the 13C CDCl3 peak isbelow. The peaks show up 20 Hz downfield of the original peak(s).  Proton experiments are completely ok!

The problem seems like to originate from the probe.  You may recall that a few months ago, we had at least one sample break inside the probe.  This caused breakage of the probe insert – plus, the RF coils were bent out of alignment.  Although we were able to get back to a working state – it is most likely that the problem has returned.  We’ll take a look at the probe locally in the next few working days, but the probe will likely need to be sent to Bruker for repair.  Bruker usually does not have a back-up ATM probe to provide, but they are checking to see if this is possible.  I’ll continue to update all the NMR users as I learn the plan moving forward.

In the meantime… another reminder….

**Make sure all NMR caps are FULLY on the NMR tubes**

If the caps are not completely pushed onto the NMR tube, the sample is too long and can break in the probe.  When I checked the rack even this week – I’m finding several tubes that are hanging too long and are caps not properly placed.  Also, don’t use caps that have split. I’ll be contacting users about this in the future – and giving stern warnings and/or remove access to the instrument. Please follow the procedures as trained so that the instrumentation will continue to provide quality data without hardware issues!  Attached is Norrell’s directions for properly placing a cap on an NMR tube for the SampleJet.  I have several Norrell NMR tubes with these marks and would be happy to show anyone who is interested.

**Use only pristine NMR tubes**

Do not use NMR tubes that have been cracked at the top.  The NMR cap cannot be properly seated on a damaged tube.  If we find NMR tubes that are too short – they will be pulled from the system.  Also, be sure the outside of your NMR tube is completely clean!  Start by cleaning your tube thoroughly in your lab.  Use a Kimwipe to clean the NMR tube further before placing it in the magnet.

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