Details

Autor(en) / Beteiligte

• Burrow, Timothy E.
• Burns, Darcy C.
• Krishnamurthy, Krish
• Reynolds, William F.

Titel

CRAPT: an improved version of APT with compensation for variations in JCH

Ist Teil von

• Magnetic resonance in chemistry, 2014-05, Vol.52 (5), p.195-201

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• A modified version of the attached proton test (APT) sequence for 13C spectral editing, which we call CRisis‐APT (CRAPT), is developed and tested on representative organic compounds. CRAPT incorporates 13C compensation for refocusing inefficiency with synchronized inversion sweeps (CRISIS) pulses in combination with 1H broadband inversion pulses to give improved compensation for variations in 1JCH along with improved refocusing efficiency. It is shown that CRAPT gives edited 13C spectra with only small losses in sensitivity (between 8% and 15% for strychnine, 1, menthol, 2, cholecalciferol, 3, and isotachysterol, 4), compared with basic 13C spectra obtained on the same compounds. CRAPT also gives significantly better signal/noise than DEPTQ for nonprotonated carbons. Therefore, we conclude that CRAPT is an improvement over APT or DEPTQ or a combination of DEPT135 with a full 13C spectrum for routine 13C spectral editing of organic compounds. Copyright © 2014 John Wiley & Sons, Ltd. A version of attached proton test incorporating compensation for refocusing inefficiency with synchronized inversion sweep pulses to provide improved compensation for variations in 1JCH is developed and tested on four representative organic compounds. It provides edited 13C spectra with only small sensitivity losses (7‐15%) compared with standard 13C spectra and better results than DEPTQ for quaternary carbons.