Automated NMR data processing by symmetry filters & a window on selective excitation / submitted by Helmut Sengstschmid

• VerfasserIn: Sengstschmid, Helmut
• Place / Publishing House: 1997
• Year of Publication: 1997
• Language: English
• Physical Description: 206 S.; graph. Darst.; Zsfassung

eng: New programs for the automated data processing of nuclear magnetic resonance (NMR) spectra are introduced. These programs are based on pattern recognition algorithms making use of the symmetry properties of multiplets. The sensitivity and the quality of INADEQUATE spectra is improved by the SATIS program. PROSIT constructs one-dimensional proton chemical shift spectra from reflected, purged or z-filtered J-spectra. A thorough comparison of these three experimental techniques is given. The third program (COMEX) aims at the automated analysis of double-quantum correlation spectra (DQF-COSY). First COMEX determines the chemical shifts via strip-symmetrization. In a second step it constructs a chemical shift grid and then searches the intersections of the grid for multiplets. This grid search is a powerful principle to make the algorithm both faster and more reliable. To demonstrate the power of these programs the spectra of complex steroids (cholesterol and 4- androsten-3,17-dione) are analyzed. The second part of this thesis introduces a new technique to observe the behavior of the magnetization during a selective pulse. By implementing the pulse as a DANTE sequence it is possible to use the interpulse delays to acquire the current magnetization. This experiment has the advantage that the effects of relaxation, inhomogeneous static and radio-frequency fields and radiation damping can be investigated directly.