Nmr Spectroscopy Lab Report

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Introduction of NMR spectroscopy Nuclear Magnetic Resonance (NMR) spectroscopy is a form of absorption spectroscopy by which a nuclei under investigation absorbs the energy from an external magnetic field and resonances or excites from a low energy state to a high energy state. It involves the disintegration of spin state into two spin states of unequal energy. The emerging radiofrequency is absorbed in a magnetic field resulting to the magnetic properties of the nuclei which getting up from the axial spin. Hence, different NMR absorption spectrum can be obtained which contains one to several groups of absorption lines in the radiofrequency part of the electromagnetic spectrum depends on the particular nucleus. Apparently, the location of peaks…show more content…
For the frequency sweep method, the precession frequency is permanent if the applied magnetic field is unchanged and the frequency of the radiofrequency field must be changed for resonance. Therefore, resonance is achieved by keeping the applied magnetic field constant and scanning the radiofrequency transmitter through the continuous variation in oscillating frequency. On the other hand, the field sweep method is achieved by continuous variation in the magnetic field but keeping the oscillating frequency constant. Among the two sweep methods, field sweep method is the most common method utilized in NMR. This is because of the ease of changing the magnetic field than the radiofrequency radiation in order to bring about resonance in nuclei. [3] 5. Radiofrequency transmitter It is used to generate the radiofrequency radiation which is needed to induce transition in the nuclei of the sample from the lower energy state to the higher energy state. It is attached at the right angles to the path of the field around the sample probe which is perpendicular to the magnetic field in order to achieve the maximum interaction with the sample. The oscillator then irradiates the sample with radiofrequency radiation and transmits radio waves of fixed frequency such as 60, 100, 200 or 300 MHz to a small coil that drives the sample in the probe. [3] 6. Radiofrequency
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