NMR: Difference between revisions
From Pumping Station One
No edit summary |
No edit summary |
||
| Line 50: | Line 50: | ||
The instrument thus strikes a fairly wonderful balance of being pretty approachable. | The instrument thus strikes a fairly wonderful balance of being pretty approachable. | ||
= Introductory Theory = | = Introductory Theory = | ||
| Line 100: | Line 92: | ||
** Placed into an NMR Tube: A thin and long glass tube that holds your sample. | ** Placed into an NMR Tube: A thin and long glass tube that holds your sample. | ||
** Sample spinner: A white piece of plastic that goes around the NMR tube. This serves two purposes: | ** Sample spinner: A white piece of plastic that goes around the NMR tube. This serves two purposes: | ||
*** It keeps the sample centered in the instrument | *** It keeps the sample centered in the instrument's probe | ||
*** It allows the sample to the spun while inside the tube. (This is done with compressed air that is supplied to the NMR). Spinning allows for better spectra to be taken. | *** It allows the sample to the spun while inside the tube. (This is done with compressed air that is supplied to the NMR). Spinning allows for better spectra to be taken. | ||
* The instrument: | * The instrument: | ||
** Sample gauge: There is a small hole on top of the unit toward the front. This is merely to set the height of the sample spinner. | ** Sample height gauge: There is a small hole on top of the unit toward the front. This is merely to set the height of the sample spinner against your NMR tube. | ||
** | ** Lifing the top lid of the instrument, one will see a few things: | ||
** | *** In the center, one sees the probe where the sample is inserted. | ||
** There is also a switch that turns the sample spinner on and off, as well as an adjustment to change the spinning speed. | *** One will also see a button that uses compressed air to eject the sample upward when pressed. | ||
*** There is also a switch that turns the sample spinner on and off, as well as an adjustment to change the spinning speed. | |||
== Running your first sample: Tap Water == | |||
* Find an NMR tube to use and fill it with plain water to somewhere between 1/3 to 1/2 the height of the tube. | |||
* Find the sample spinner. It may be inside of the instrument's probe. Never have your face over the probe while ejecting the sample probe entrance -- air pressure is used to push the sample out of the instrument when the eject button. To eject, have your hand around the entrance to the probe and press the eject button inward slowly. The sample should gently rise upward and you should be able to retrieve it. | |||
* Place your NMR tube filled with water into the sample spinner (the white piece of plastic that goes around the tube) | |||
* The height of the tube inside the spinner should be set with the height gauge on the instrument. | |||
* The tube can now be placed into the instrument. Hold the eject button partway and release it slowly to allow the tube to gently fall into the probe. | |||
* Use the PNMR software to capture and observe the resulting spectrum. | |||
== Operation / Background == | == Operation / Background == | ||
| Line 181: | Line 182: | ||
* [https://www.aiinmr.com/guide-to-processing-1h-nmr-data-using-nuts-software/ Guide to Processing 1H NMR data using NUTS Program] | * [https://www.aiinmr.com/guide-to-processing-1h-nmr-data-using-nuts-software/ Guide to Processing 1H NMR data using NUTS Program] | ||
= | = Functional Status / Service Log = | ||
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. | |||
* 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> | |||
* October 2024: Switchmode PSU in other giant box has failed. 4A main fuse blown and a capacitor on a PSU supplying +5V +/-15V has blown. A second power supply providing 28V in the same box has yet to be tested. Repairs pending. | |||
* November 2024: Switchmode PSUs have had just about every capacitor replaced and some giant mosfet. Verified +5V, +-15V, and 28V present. | |||
