NMR: Difference between revisions
From Pumping Station One
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* Probe - The detector of an NMR. Most commonly, this is Hydrogen-1, but probes for other elements exist. The probe is ultimately just a coil, but it is tuned to the element of interest. | * Probe - The detector of an NMR. Most commonly, this is Hydrogen-1, but probes for other elements exist. The probe is ultimately just a coil, but it is tuned to the element of interest. | ||
* PPM - The unit "chemical shift" is measured in when looking at NMR spectra (x-axis). This corresponds to the shift from the reference frequency from 0ppm. | * PPM - The unit "chemical shift" is measured in when looking at NMR spectra (x-axis). This corresponds to the shift from the reference frequency from 0ppm. | ||
* Upfield / Shielded / Lower Energy - Peaks occurring closer to 0ppm (near the right side of x-axis). | |||
* Downfield / Deshielded / Higher Energy - Peaks further left on the x-axis (away from 0ppm). | |||
== History == | == History == | ||
* First generation instruments would use a constant RF frequency but ramp the magnetic field up slowly, and this is in fact what this unit did in its original form. | * First generation instruments would use a constant RF frequency but ramp the magnetic field up slowly, and this is in fact what this unit did in its original form. | ||
