Re: AMMRL: Re: cryoprobes for a 'routine' NMR instrument

From: Ralph Adams <ralph.adams_at_manchester.ac.uk>
Date: Fri, 20 Sep 2019 20:00:24 +0000

Dear Tom,

I can answer with regard to prodigy probes - I have two, one at 500 MHz and one at 400 MHz.

The probe cannot be used without cooling.

You can take the probe out relatively easily but I rarely do. There are only 2 reasons to use a different probe: VT at >70C or <-40C, or acquisition of nuclei with frequencies very close to deuterium. Otherwise, why would you use a rt probe? The cost of running is about the same as the liquid nitrogen for 1 magnet, probably about 70 litres a week (and a service every 2 years which is probably $10k but you’d have to ask Bruker, I do my service in house for about $800 in parts). If you take the probe out it can take a couple of days to reach a decent vacuum after you put it back.

Normal 5 mm tubes are fine.

If you can get the money you should buy one. The sensitivity is amazing compared to rt, I have a 3 minute 13C experiment on the day queue which serves 90% of my chemists carbon requirements and would take about half an hour on a rt probe.

Best wishes,

Ralph

Ralph W. Adams PhD
Head of NMR, Department of Chemistry, University of Manchester, Manchester, UK

> On 20 Sep 2019, at 20:43, Tom Pratum <tkp9551_at_gmail.com> wrote:
>
> Hello AMMRL List-
> We are currently pursuing funding for a new instrument. One question has come up regarding whether it is worth purchasing a cryoprobe. This instrument is used for a lot of routine/undergrad teaching and research. I am wondering about a couple of questions regarding a nitrogen cooled probe:
>
> 1. Can the probe be used without cooling? If there is no cooling, is it basically like a rt probe?
>
> 2. If the probe is not used for long periods - presumably a rt multinuclear probe would be in place most of the time - does that cause problems when it is used? I guess another way to put it would be whether taking it in and out of the magnet multiple times seems reasonable?
>
> 3. My assumption is that no special nmr tubes are used for a cryoprobe - let me know if this is not the case.
>
>
> Thanks very much in advance for any responses!
>
>
> Tom Pratum
> Southern Oregon University
Received on Fri Sep 20 2019 - 10:01:11 MST

This archive was generated by hypermail 2.4.0 : Wed Jun 21 2023 - 17:14:14 MST