NMR: Difference between revisions
From Pumping Station One
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* Downfield / Deshielded / Higher Energy - Peaks further left on the x-axis (away from 0ppm), require more energy to bring them into resonance. | * Downfield / Deshielded / Higher Energy - Peaks further left on the x-axis (away from 0ppm), require more energy to bring them into resonance. | ||
* Gyromagnetic Ratio or Gamma γ - This is a fundamental property of a given isotope. The higher this number, the more signal it produces in NMR. For Hydrogen-1 this is 42.58MHZ / Tesla. Hydrogen-1 has one of the higher Gyromagnetic Ratios and the presence of hydrogen in just about everything makes it one of the most commonly analyzed isotopes in NMR spectroscopy. | * Gyromagnetic Ratio or Gamma γ - This is a fundamental property of a given isotope. The higher this number, the more signal it produces in NMR. For Hydrogen-1 this is 42.58MHZ / Tesla. Hydrogen-1 has one of the higher Gyromagnetic Ratios and the presence of hydrogen in just about everything makes it one of the most commonly analyzed isotopes in NMR spectroscopy. | ||
* Shim - NMR relies on having a very homogeneous magnetic field. "Shimming" the magnet refers to adjusting it, and this is achieved by both a mechanical adjustment as well as a electronic coils that further fine-tune the magnetic field. The mechanical adjustment requires a brass, copper, or wooden flathead to turn a screw deep inside the instrument. Use of typical iron-containing screwdriver will result in it distorting the field (making adjustment challenging), and it'll try to consume the screwdriver the whole time you are trying (it's not worth it). | |||
== History of NMR as a technique == | == History of NMR as a technique == | ||
