Belton P S, Gil A M, Tanner S F
AFRC Institute of Food Research, Norwich Research Park, Colney, UK.
Solid State Nucl Magn Reson. 1992 Jun;1(2):67-71. doi: 10.1016/0926-2040(92)90018-5.
The CP/MAS 13C NMR spectra of crystalline L-leucine and DL-leucine at 7 T are compared with previously reported spectra at lower field strengths. An increasing dominance of chemical shift effects over residual 14N-13C dipolar interactions is observed on the C alpha and C beta splittings with increasing field strength. A new structure is observed in the 25 ppm region of both samples. The spectra in this region were assigned by application of the depolarisation-repolarisation method. The assignment showed differences in the ordering of peaks between solid state and liquid state chemical shifts.
