Hello everyone, an opportunity has presented itself and I would like to hear your thoughts.
Recently I have purchased a 'time share' or a 300mHz NMR however I have found that I don't run nearly enough samples to fill up all of my purchased
time. I am asking you, the science madness community, if there would be any interest in having samples run on the NMR. Currently, I own deuterated
chloroform and DMSO as solvents. I have deuterated methanol as well but it gives a poor spectrum on this machine. If there is enough interest I can
buy other solvents as well. I also know that not everyone is good at reading NMR spectrums thus as part of this service I will send you the spectrum
and I will do my best to interpret the spectrum as well if you would like me to.
This idea is still at the early stages but I would like to know if any of the community here would like samples run. I would have to charge for the
solvent used for the sample but other than that I would do it for practically free. I haven't worked out the price yet but I am guessing it would cost
around $20 dollars a sample (plus the postage to send the sample to me) , which is a real bargain compared to the $1,000 a professional NMR service
will cost.
Let me know what you all think!Magpie - 31-7-2016 at 09:41
There's been a time or two in the last 11 years that I would have used your service.
I think this is a good idea. I hope it works out for you and us.JnPS - 31-7-2016 at 10:17
YESSSSSSSS!!!!! The NMR at my college has been broken for the past few years with no mention of when it could or would be fixed so I've been using IR
spectra for confirming the products of my organic syntheses, but I would love to be able to get NMR spectra done; not to mention I've always liked
interpreting spectra, the puzzle is always fun. I know for IR you only need like a drop of sample but I'm not familiar with NMR usage (in class they
really only teach how to interpret it), would you only need like 1-2mL of a sample or 5mL+? Steam - 31-7-2016 at 10:21
Yes, I only need about 0.2 grams of sample to do NMR, though I would probably ask for at least 0.5 just to be safe. For liquids I need about 1 mL ish.
Metacelsus - 31-7-2016 at 13:40
0.2 grams is way too much. 30 mg should be sufficient for 1H for almost any compound, and for 13C for most compounds.
(see http://nmr.chem.umn.edu/samprep.html)
[Edited on 8-1-2016 by Metacelsus]DJF90 - 31-7-2016 at 14:13
I routinely aquire 1H and 19F spectra on 3 mg samples. For a 13C spectum you're talking more like 20 mg for a decent looking spectrum (assuming your
material is clean). Much less than that and it can be difficult to pick the peaks from the baseline.bolbol - 31-7-2016 at 16:21
I am not familiar with such instruments but is this the one that tells you the chemical composition of an unknown compound/mixture?Metacelsus - 31-7-2016 at 16:37
In my experience, it's mostly used for structural determination of pure, unknown compounds. It can also help in evaluating the chemical composition of
a mixture, but for this GC-MS is usually better (assuming the components are volatile enough).bolbol - 31-7-2016 at 16:50
The compounds I have are actually hard silicate minerals.. I can powder them but they are pretty much insoluble and non volatile.. I have a few
different types of quartz and I want to know the impurities in them(compounds besides silicon and oxygen)Steam - 31-7-2016 at 17:08
0.2 grams is way too much. 30 mg should be sufficient for 1H for almost any compound, and for 13C for most compounds.
(see http://nmr.chem.umn.edu/samprep.html)
You're absolutely right! I am not sure what I was thinking with 0.2 (way too early in the morning for me)! Yes for the machine being used, 0.03-0.05
grams of sample is what we usually end up running. Though I can adjust the acquisition time to try to get peaks out of more dilute solutions. If you
want FT-IR done also you probably should throw in a bit more as well!
Glad to see some interest in this! I am going to price things out and post something a bit more formal!Steam - 31-7-2016 at 20:28
The compounds I have are actually hard silicate minerals.. I can powder them but they are pretty much insoluble and non volatile.. I have a few
different types of quartz and I want to know the impurities in them(compounds besides silicon and oxygen)
I am offering a Hydrogen NMR, which is different from the Si 29 NMR you would need. As mentioned previously this sort of spectrum is most useful for
understanding the structure of pure/mostly pure organic compounds. I could however offer a FT-IR analysis of your powdered minerals. This could
potentially help you. I also have access to an electron microscope which can perform MLA (mineral liberation analysis). It gives an x-ray spectrum
which qualitatively tells mineral composition. U2U me if you want more information.
