Introduction to Soil Chemistry

25
20
% Transmittance
10 15
5
0
Sodium Humate
H
O H O
nuclear magnetic resonance 167
4000 3500 3000 2500 2000 1500 1000
Toluene/Hexanoic acid/Octanal
12
Acid
–H
Aldehyde
–H
10
CH 3,
CH 2
8
Wave numbers (cm) –1
Aromatic
–H
6
from the pellet (see C in Figure 8.7). There are gas cells for obtaining spectra
of gases, and many other methods for obtaining spectra from liquid and solid
samples are available but not as frequently used as these [22–26].
8.12. NUCLEAR MAGNETIC RESONANCE
Aliphatic
–CH 2
Aliphatic
–CH 2
–CH 3
TMS
Figure 8.12. Infrared spectra of a KBr pellet of 3% sodium humate (Aldrich) and an NMR spectrum
of a mixture of toluene, hexanoic acid, and octanal. The functionalities responsible for the
absorptions are labeled.
Although some useful and interesting data have been obtained by extracting
various components from soil and analyzing them by nuclear magnetic reso-
4
2
0
ppm