3. Isotope Spin %age γ
I abundance MHz/T
1
H 1/2 99.985 42.575
2
H 1 0.015 6.53
13
C 1/2 1.108 10.71
14
N 1 99.63 3.078
15
N 1/2 0.37 4.32
17
O 5/2 0.037 5.77
19
F 1/2 100 40.08
23
Na 3/2 100 11.27
31
P 1/2 100 17.25
Common NMR Active Nuclei
4. Alignment of Spins in a
Magnetic Field
spin
magnetic moment
B0 field
M
M=0
5. Energy in a Magnetic Field
(Zeeman Splitting, Spin ½)
E+1/2= −γB0/2 E-1/2= +γB0/2
P+1/2= 0. 5000049 P-1/2= 0.4999951
1.5T, T=310K, P(E)∝exp(−E/kT)
mI = +½ mI = −½