5
•
";"0> 4
0>
g
r:::
~ 3
r:::
g
8 2
~
.s::
a.
ai
o
Non-Metals and Sulphides
73
10
20
30
40
50
60
70
Depth in sediment/em
Fig. 3.1
Bar graph of acid volatile sulphide in a sediment core collected from Blelham Tarn on
30 July 1980; • = Rowlatt's mean data for the sediments of this lake 221 (distillation/iodometric
procedure) (from [226]).
Davison and Lishman [226] described a method in which sulphide is released from
the sediment using 5.93 mol I-I hydrochloric acid, and the resulting solution is separated from the sediment by filtration in a sealed system of syringes. The concentrated
sulphide is determined spectrophotometrically at 670 nm as ethylene blue. The limit
of detection is 2 mg kg- 1 expressed as mass of sulphide in dry mass of sediment. The
relative standard deviation was 5 % for a sediment containing 118 mg kg- 1 sulphide.
Figure 3.1 shows values obtained for a sediment core taken from Blelham Tarn in
the English Lake District. The core was sampled by inserting syringes fitted with
75-cm 21 G stainless steel needles into pre-drilled 3-mm diameter holes in the core
liner. They were at 1.3-cm depth intervals and were sealed with polythene tape. This
technique enables a sub-sample to be removed from the core without exposure to
oxygen. All measurements were performed in duplicate within 2d of the core being
collected. Determinations were in good agreement with those of Rowlett [227] who
used a conventional distillation-iodometric procedure for determining sulphide.
Landers et al. [228] have described methods for the determination of organic
sulphur (carbon bonded sulphur and ester sulphate) and inorganic sulphur (sulphate
and sulphide) in lake sediments. Some results obtained by applying these methods to
anaerobic lake sediment samples are shown below:
m mol kg-l
Total S
229
± 18
HCl-S
1.56 ± 0.36
Zn-HCl-S
75.9 ± 9.4
HI-S
82.5 ± 12.5
SO.S
35.3 ± 2.5
C-S
146
± 17.7
C-0-S0 3
45.3 ± 12.4
•
";"0> 4
0>
g
r:::
~ 3
r:::
g
8 2
~
.s::
a.
ai
o
Non-Metals and Sulphides
73
10
20
30
40
50
60
70
Depth in sediment/em
Fig. 3.1
Bar graph of acid volatile sulphide in a sediment core collected from Blelham Tarn on
30 July 1980; • = Rowlatt's mean data for the sediments of this lake 221 (distillation/iodometric
procedure) (from [226]).
Davison and Lishman [226] described a method in which sulphide is released from
the sediment using 5.93 mol I-I hydrochloric acid, and the resulting solution is separated from the sediment by filtration in a sealed system of syringes. The concentrated
sulphide is determined spectrophotometrically at 670 nm as ethylene blue. The limit
of detection is 2 mg kg- 1 expressed as mass of sulphide in dry mass of sediment. The
relative standard deviation was 5 % for a sediment containing 118 mg kg- 1 sulphide.
Figure 3.1 shows values obtained for a sediment core taken from Blelham Tarn in
the English Lake District. The core was sampled by inserting syringes fitted with
75-cm 21 G stainless steel needles into pre-drilled 3-mm diameter holes in the core
liner. They were at 1.3-cm depth intervals and were sealed with polythene tape. This
technique enables a sub-sample to be removed from the core without exposure to
oxygen. All measurements were performed in duplicate within 2d of the core being
collected. Determinations were in good agreement with those of Rowlett [227] who
used a conventional distillation-iodometric procedure for determining sulphide.
Landers et al. [228] have described methods for the determination of organic
sulphur (carbon bonded sulphur and ester sulphate) and inorganic sulphur (sulphate
and sulphide) in lake sediments. Some results obtained by applying these methods to
anaerobic lake sediment samples are shown below:
m mol kg-l
Total S
229
± 18
HCl-S
1.56 ± 0.36
Zn-HCl-S
75.9 ± 9.4
HI-S
82.5 ± 12.5
SO.S
35.3 ± 2.5
C-S
146
± 17.7
C-0-S0 3
45.3 ± 12.4