The most critical problem of NMR spectroscopy and magnetic resonance imaging (MRI) is the relatively low sensitivity compared to other forms of spectroscopy, limiting the applicability of these techniques. Most of the existing research focused on trying to alleviate these problems through hyperpolarization techniques, strong magnetic fields, low temperature experiments (<25K), and pulse sequence development. Going beyond the previously stated methods, researchers found that the implementation of smaller resonant coils is a more convenient and effective way to alleviate the problem of low sensitivity in NMR spectroscopy and magnetic resonance imaging. In this work, a systematic optimization of the parameters for micro-coil probes and magic-angle coil spinning (MACS) probes was carried out with various common NMR nuclear species such as 1H, 31P, 23Na, 79Br on two NMR spectrometers (200 MHz and 500 MHz). The optimized wire diameter, coil diameter, number of turns, the inner and outer diameters of the capillary, the matching capacitors etc have been obtained and demonstrated with a real biological system. In addition, we found that the conventional placement of the sample within the glass tube wrapped by a coil yields a lower signal and sensitivity when compared to coating the sample onto the coil prior to wrapping around the capillary. A new method of performing MACS experiment with micro-coil technology, therefore, was subsequently proposed, namely, micro surface coil magic angle spinning (MISCMAS). The optimized experimental conditions were then determined with both liquid and solid state samples.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0525111-160256 |
| Date | 25 May 2011 |
| Creators | Ke, Wea-len |
| Contributors | Kuo-Mei Chen, Shangwu Ding, Hsiu-Wei Chen |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0525111-160256 |
| Rights | withheld, Copyright information available at source archive |
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