dear group members
i will mention again that we had this problem with an older bruker shim
stack and they had a extra brass tube that narrows the bore above the
spinner to center the sample better as it goes in. you might want to ask
about this.
yours
charles amass
smith college
David Kiemle wrote:
>
> We had similar problems with our Bruker AVANCE 300 MHz
> instrument. It is an open access instrument and no matter
> how many "instructions", warning signs or threats students
> always found a way to break the inserts or worse. Our
> solution was to put an autosampler (24 pack) on the system.
> We have had it now for about a year, and have not had any
> problems with inserts.
>
> David J. Kiemle
> SUNY ESF
>
> -----Original Message-----
> From: Wei Wycoff [mailto:WycoffW@missouri.edu]
> Sent: Thursday, June 07, 2001 5:04 PM
> To: bruker-users-mail@bloch.cchem.berkeley.edu;
> ammrl@wwitch.unl.edu
> Subject: QNP probe insert
>
> Hi all,
>
> Sorry this is an old topic that people have discussed a lot
> before. The
> glass insert in the Bruker QNP probe (ARX250) in our lab
> break frequently.
> We have asked users to buy good tubes, we check magnet level
> routinely, we
> put up big red-letter CAUTION sign to ask users to turn on
> air before
> inserting sample and turn off spin before ejecting sample,
> we took off the
> springs in the depth gauge so that it wont slide from the
> 1.8 cm position
> ... , and it still breaks! We have never had a broken
> insert on our other
> Bruker instruments which do not have QNP probe. I'm
> beginning to think
> it's due to the QNP switching that may cause shocks to the
> insert and
> therefore break it. The NMR is used routinely for 31P and
> 19F, so the QNP
> switch is used a lot. Spraying a little WD-40 once every
> few years can
> help it to be less noisy.
>
> It seems the only thing left to do is to stock up the glass
> inserts. The
> cost is $80 when we bought from Bruker two years ago. I
> remember seeing
> other vendors' price being less but can't find it. Could
> any of you please
> remind me about the names of these vendors?
>
> Thanks for all your help.
>
> Wei
>
> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:>
> <:> <:> <:>
>
> Wei Wycoff
> Department of Chemistry
> 601 S. College Ave.
> University of Missouri-Columbia
> Columbia, MO 65211
> USA
>
> voice: (573) 882-3291
> fax: (573) 882-2754
> email: WycoffW@missouri.edu
> http://chem.chem.missouri.edu/nmr/nmr.html
>
> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:> <:>
> <:> <:> <:>
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