A Novel Composite 90° Pulse Sequence Which Provides Distortionless NMR Spectra and Suppresses without Destroying the Water Magnetization
✍ Scribed by P. Sodano; C. Landon; M. Ptak
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 154 KB
- Volume
- 133
- Category
- Article
- ISSN
- 1090-7807
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✦ Synopsis
A novel 90 degrees composite pulse sequence which allows one to record 1D and 2D NMR spectra without disturbing the water magnetization is described. A home-written program was used to optimize the pulse angles for which the pulse sequence response fitted best the desired excitation profile, producing a neat and distortionless spectrum with a broad null excitation at the carrier frequency. The resulting pulse sequence was first evaluated using the simulation program "PENCIL" and then tested on two protein samples. A 3.5 degrees phase shift of the last pulse was required to cancel correctly the water signal. The pulse scheme was appended to a NOESY pulse sequence. Inspection of the water cross section revealed interactions between water and some protons of drosomycine, a small insect antifungal protein.