Organic compounds in sludges 221
20.00
30.00
40.00
min
1.500
1.000
0.500
0.000
a
b
c
d
e
f
(A)
20.00
30.00
40.00
min
400
Relative response
300
200
100
000
(B)
20.00
30.00
40.00
min
50.00
30.00
40.00
20.00
10.00
0.00
(C)
Figure 10.2 Typical chromatograms of VFAs. (A) 20 mg/LVFAs standard solution. (B) Free CFAs slurry
samples spiked with 20 mg/L with standards. (C) Routine pig slurry analysis. Peaks: a, acetic
acid; b, propionic acid; c, isobutyric acid; d, butyric acid; e, isolvaleric acid; f, valeric acid.
Reprinted from P. Peu et al, International Journal of Environmental Analytical Chemistry, 2004,
84, 1017, © 2004,Taylor and Francis [44].