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[[Category:Science]]
[[Category:Science]]https://wiki.pumpingstationone.org/index.php?title=NMR&action=edit
Yes. There are many, many types of spectroscopy. This ones involves magnets and radio frequencies, and can (potentially) tell you things about a liquid which is placed into a thin/tall glass tube. The principle under which it operates is the same as an MRI scanner; however, rather than making pictures, it makes squiggly lines. It is not a [https://www.youtube.com/watch?v=9Gq3UEAiWio Gas Chromatograph], nor a Mass Spec, as a few have called it...
Yes. There are many, many types of spectroscopy. This ones involves magnets and radio frequencies, and can (potentially) tell you things about a liquid which is placed into a thin/tall glass tube. The principle under which it operates is the same as an MRI scanner; however, rather than making pictures, it makes squiggly lines. It is not a [https://www.youtube.com/watch?v=9Gq3UEAiWio Gas Chromatograph], nor a Mass Spec, as a few have called it...
Unlike some other techniques which allow for elements to be looked at (ICP-MS, ICP-OES, XRF, etc.), this one is concerned with compounds and most commonly with Hydrogen or Carbon. It can be used to determine the structure of a compound and so lends itself to organic compounds. Only certain elements (or more accurately, certain isotopes of those elements) are NMR Active (meaning, in essence, they will behave like magnets), and it is through putting those into resonance that we can learn more about how they exist within a sample.
Unlike some other techniques which allow for elements to be looked at (ICP-MS, ICP-OES, XRF, etc.), this one is concerned with compounds and most commonly with Hydrogen or Carbon. It can be used to determine the structure of a compound and so lends itself to organic compounds. Only certain elements (or more accurately, certain isotopes of those elements) are NMR Active (meaning, in essence, they will behave like magnets), and it is through putting those into resonance that we can learn more about how they exist within a sample. The technique can be used to identify what something is, and also to quantify how much of various parts are present.
== But Why? ==
== But Why? ==
** Well, it's an experiment. It might serve as a hands-on, gentle introduction to spectroscopy, science, analytical instrumentation, etc. We're pretty sure no makerspace in the world has put one of these inside of it, but given the right community and encouragement around it, maybe something interesting could happen.
** Well, it's an experiment. It might serve as a hands-on, gentle introduction to spectroscopy, science, analytical instrumentation, etc. We're pretty sure no makerspace in the world has put one of these inside of it, but given the right community and encouragement around it, maybe something interesting could happen.
** Activities, applications, and maybe some classes are pending.
** Activities, applications, and maybe some classes are pending.
* While NMR makes a lot more sense with a grounding in organic chemistry (and thus potentially intimidating), it is worth pointing out that one could easily learn how to operate the instrument and get meaningful results if one has a specific application in mind. Quantification of ethanol in a sample could easily be performed with less than an hours time in initial training and no need for an organic chemistry background.
== Getting Involved / Authorization ==
== Getting Involved / Authorization ==
The instrument thus strikes a fairly wonderful balance of being pretty approachable.
The instrument thus strikes a fairly wonderful balance of being pretty approachable.
== Functional Status ==
== Functional Status / Service Log ==
Full turnup and test complete with H1 and C13 probes functional.
Full turnup and test complete with H1 and C13 probes functional.
Celebrations were had by drinking beer with the machine (beige box partaking as well), and relative quantification of ethanol vs water were undertaken with wobbly, but within an order-of-magnitude results. Further adventures planned... It probably works at a given point. Probably needs electronic shimming if it has been sitting for a while.
Celebrations were had by drinking beer with the machine (beige box partaking as well), and relative quantification of ethanol vs water were undertaken with wobbly, but within an order-of-magnitude results. Further adventures planned... It probably works at a given point. Probably needs electronic shimming if it has been sitting for a while.
* Feburary 2023: Failed Switchmode PSU in the shim control box was replaced with a center-tap transformer and a self-designed +/-15V 7815/7915 linear PSU on an aluminum substrate PCB.
* Feburary 2023: Failed Switchmode PSU in the shim control box was replaced with a center-tap transformer and a self-designed +/-15V 7815/7915 linear PSU on an aluminum substrate PCB.
* As of March 2023, it still works.
* October 2023: Primary Hard Drive (32GB SSD failed.) Recovered onto some random hard drive with <code>dddrescue</code>. Instrument online again. Pending analysis of corrupted files via <code>ddru_ntfsfindbad</code>
= Introductory Theory =
= Introductory Theory =
= Operation =
= Operation =
== Overview ==
== Overview ==
NMR uses thin (5mm diameter) glass tubes for samples. A sample needs to be liquid. Special solvents are often used to prepare a sample, but, direct analysis is possible. No harm in trying and seeing what happens.
NMR uses thin (5mm diameter) glass tubes for samples. A sample needs to be liquid. Special solvents are often used to prepare a sample, but, direct analysis is possible. No harm in trying and seeing what happens. Advanced techniques might involved solvent suppression pulse sequences or deuterated solvents.
== Hardware ==
== Hardware ==
== Operation / Background ==
== Operation / Background ==
* Unless performing more elaborate techniques, NMR spectra are generally a squiggly line.
* Unless performing more elaborate techniques, NMR spectra are generally a squiggly line.
** Y-Axis is intensity. Simple enough. If you take the area underneath a peak and add it up (integrate), you can now say something about how much of something exists and begin to quantify it.
** Y-Axis is intensity. Simple enough. The taller a peak, the more of something there is. If you take the area underneath a peak and add it up (integrate it), you can now say something about how much of something exists and begin to quantify it.
** X-Axis has quirks:
** X-Axis has quirks:
*** It technically represents the amount the frequency of whatever is being analyzed is shifted from the signal from TMS (which is used for calibration and whose single peak is considered 0).
*** It technically represents the amount the frequency of whatever is being analyzed is shifted from the signal from [https://en.wikipedia.org/wiki/Tetramethylsilane Tetramethylsilane]. TMS is a commonly used for calibration and whose single peak is defined to be 0ppm.
*** Also, 0 starts from the right side. Higher frequencies are to the left 0 on the X-Axis (Historical Quirks)
*** Also, 0 starts from the right side. Higher frequencies are to the left 0 on the X-Axis (Historical Quirks)
*** Technically, we are measuring how many Hertz higher something is than where the signal for TMS is.
*** Technically, we are measuring how many Hertz higher something is than where the signal for TMS is.
*** In practice, we never refer to this in Hz because the amount of shift would depend on the strength of the NMR we have. Since it would be nice to sensibly compare data across different instruments, the amount of Hertz shift is divided by the frequency of the instrument. We call this value PPM.
*** In practice, we never refer to this in Hz because the amount of shift would depend on the strength of the NMR we have. Since it would be nice to sensibly compare data across different instruments, the amount of Hertz shift is divided by the frequency of the instrument. We call this value PPM. Do not confused the usages of "PPM" here for perhaps the more common use case in other techniques where one would be referring to concentration of a sample. In all cases, it stands for "Parts per million", but here it is important to remember ppm is the x-axis, which has more to do with what something is and not with how much there is.
= Software =
= Software =
|-
|-
|CDCl<sub>3</sub>|| Deuterated Chloroform ||Most common solvent used in NMR
|CDCl<sub>3</sub>|| Deuterated Chloroform ||Most common solvent used in NMR
|-
| || Sodium Acetate C13 ||
|}
|}
* Yep, there's no 'D' on the periodic table. When you see a 'D' in a chemical formula, it is [https://en.wikipedia.org/wiki/Deuterium Hydrogen-2 aka Deuterium]. When this form of hydrogen is used in a compound, it is often referred to as being "Deuterated". This is a form in which the hydrogen atoms are replaced with a more rare (but stable) isotope of hydrogen. The reason for doing this is that this form of hydrogen is not "NMR Active". Normally, a strong hydrogen signal (from say, plain water) would overwhelm the incoming NMR signal, thus making it harder to see small peaks. Deuterated solvents are used because they are not NMR active and so would not contribute to the spectrum.
== Peak Splitting / Multiplicity ==
== Peak Splitting / Multiplicity ==
