Using an Autosampler Manually
Very soon, all the instruments in the UChicago Chemistry NMR Facility will be equipped with autosamplers, including the manually-operated ones. Two questions may come to mind: How? Why?
Very soon, all the instruments in the UChicago Chemistry NMR Facility will be equipped with autosamplers, including the manually-operated ones. Two questions may come to mind: How? Why?
The software running 500-3 and which will be running 600-1 is version 4.2.0 of Topspin. It works mostly the same as the Topspin we’ve been using, but there are some important differences to note. This post covers some of the key differences you’ll encounter right away.
Here’s a tip for you when acquiring long experiments manually: use the Autoshim feature. Located in the BSMS control window, clicking “Start” will ensure your shim quality stays good over long periods (~4+ hours). But when you’re done, be sure to click “Start” again to toggle it off, or else it’ll continue operating when the next user is trying to run, which will surprise them and give them inconvenience.
The most common 2D experiments on the automated systems work best if you choose the one whose names end in “-opt”; these experiments examine a preliminary PROTON8 experiment and reset the 1H spectrum window in the 2D so you get the best resolution. It’s very easy to set up, but things can go wrong if you make changes or decide you need a 2D after the 1H 1D has already been acquired. Here are some tips for success.
Many chemical structure questions can be answered with 1H-1H distance estimates derived from the 1D NOESY experiment. There are a variety of ways to set up this experiment, but we now have two short videos that UChicago users can access with their phones at the spectrometer – no homework or special prep required.
Tweaks have been made to all default 1H and 13C 1D and 2D experiment parameter sets so they have been tested as effective and are the same on all spectrometers. If you have a 10mg properly-prepared sample, you are assured of getting good data using default parameters with these experiments no matter which instrument you use.
500-1 is open, supporting walkup experiments in Searle. It’s outfitted with a different probe to provide better 13C sensitivity and capabilities of observing 31P, 11B, 195Pt, and more. Spectra are shown for a standard 10 mg/mL sample of carvone to provide a visual basis for comparison.
The new 400-2 is ready for use! With this upgrade, the spectrometer has transformed into an automated high-throughput engine for routine data acquisition. “Routine” now includes a variety of standard 2D experiments, plus 1D experiments for a growing assortment of NMR-active nuclei.
Major events took place in Week 1 of reopening, including a number of hardware and software upgrades to NMR systems. For Week 2, expect to continue using 400-1 for routine work. Other systems are actively being configured and upgraded in various ways, so please be patient.
The NMR Facility will shut down for an undetermined period starting Friday, March 20 in response to the COVID-19 pandemic. See post for precise timing.
7Li NMR is now an option on 400-1, our automated instrument in Searle.
Good news, everyone!
Thanks to the Dean of the PSD for providing funding, we’ll be upgrading 400-2 with a new console, probe, and autosampler! In mid-2020, we should see the instrument transform into something akin to 400-1, but with a more current-model probe and a 60-sample carousel on the SampleCase autosampler.