Organic compounds in soils 25
0.0
0
2
4
6
8
10
12
mAU
2.5
5.0
7.5
10.0 12.5 15.0
Minutes
17.5 20.0 22.5 25.0
a
b
27.5 30.0
Figure 2.2 Chromatograms obtained from an alkaline extract from a non-contaminated soil (a) before
and (b) after solid phase clean-up with the SD B-1 sorbent.
Reprinted from P. Sirvent et al, International Journal of Environmental Analytical Chemistry, 2009,
89, 293 © 2009 Taylor and Francis [121].
2.2.4 Methoxy groups
The determination of the methoxy group (OCH 3 ) content of soils is important in studies concerned with the degree of humification of soil organic matter. Methods used to
determine methoxy groups in soils have generally been based on volumetric modifications of the classical Zeisel method, which is a complicated and tedious procedure
requiring specialised apparatus.
Mogabhaes and Chalk et al [122] used a combination of Zeisel hydriodic acid
digestion and gas chromatography of the produced iodmethane to determine methoxy
groups in soil.
This was used to determine the content of methoxy groups in samples of soils from
Eastern Australia. A wide range in the methoxy group concentration was observed,
which accompanies the wide range in organic concentrations measured (Table 2.2).
Positive correlation (p < 0.001) was found between the methoxy group and organic C
contents of the soils.
2.3 CHLORINE CONTAINING COMPOUNDS
2.3.1 Chloroaliphatic hydrocarbons
Deetman et al [123] have devised an electron capture gas chromatographic technique
applicable to mud samples for the determination of down to 1 ng/1 of 1,1,1trichloroethane, trichloroethylene, perchloroethylene, 1,1,1,2-tetrachloroethane,
0.0
0
2
4
6
8
10
12
mAU
2.5
5.0
7.5
10.0 12.5 15.0
Minutes
17.5 20.0 22.5 25.0
a
b
27.5 30.0
Figure 2.2 Chromatograms obtained from an alkaline extract from a non-contaminated soil (a) before
and (b) after solid phase clean-up with the SD B-1 sorbent.
Reprinted from P. Sirvent et al, International Journal of Environmental Analytical Chemistry, 2009,
89, 293 © 2009 Taylor and Francis [121].
2.2.4 Methoxy groups
The determination of the methoxy group (OCH 3 ) content of soils is important in studies concerned with the degree of humification of soil organic matter. Methods used to
determine methoxy groups in soils have generally been based on volumetric modifications of the classical Zeisel method, which is a complicated and tedious procedure
requiring specialised apparatus.
Mogabhaes and Chalk et al [122] used a combination of Zeisel hydriodic acid
digestion and gas chromatography of the produced iodmethane to determine methoxy
groups in soil.
This was used to determine the content of methoxy groups in samples of soils from
Eastern Australia. A wide range in the methoxy group concentration was observed,
which accompanies the wide range in organic concentrations measured (Table 2.2).
Positive correlation (p < 0.001) was found between the methoxy group and organic C
contents of the soils.
2.3 CHLORINE CONTAINING COMPOUNDS
2.3.1 Chloroaliphatic hydrocarbons
Deetman et al [123] have devised an electron capture gas chromatographic technique
applicable to mud samples for the determination of down to 1 ng/1 of 1,1,1trichloroethane, trichloroethylene, perchloroethylene, 1,1,1,2-tetrachloroethane,