Chemistry Reference
In-Depth Information
acid to examine the collection and decomposition of organic chromium species, because
these ligands form quite stable water-soluble complexes with chromium(III) although
they are not actually present in seawater. Both these chromium(III) chelates are stable in
seawater at pH 8.1 and are hardly collected with either of the hydrated oxides. The
organic chromium species were then decomposed to inorganic chromium(III) and
chromium(VI) species by boiling with 1g ammonium persulphate per 400mL−1 seawater
acidified to 0.1M with hydrochloric acid. Iron and bismuth, which would interfere in
atomic absorption spectrometry, were 99.9% removed by extraction from 2M
hydrochloricacid solution with a
p
-xylene solution of 5% tri-iso-
Table 3.3
Vertical distribution of chromium species in the Sea of Japan and in the Pacific
Ocean
Depth (m)
Cr(III)
a
(×10
−9
M)
Cr(VI)
(×10
−9
M)
Org. Cr
(×10
−9
M)
Total Cr
(×10
−9
M)
Japan Sea (44° 11.9'N 138°56.4'E; depth 3447m)
0
1.3
2.1
4.9
8.3
10
1.4
1.7
5.9
9.0
51
1.6
1.8
4.3
7.7
102
1.2
1.7
5.3
8.2
152
1.3
1.8
4.2
7.3
203
1.2
1.8
4.6
7.6
403
1.4
2.9
5.0
9.3
602
1.1
2.3
3.7
7.1
1000
1.5
2.4
3.5
7.4
1427
1.1
3.0
4.2
8.3
1920
1.8
1.7
6.2
9.7
2417
1.1
2.1
4.6
7.8
2916
1.2
-
-
9.1
3165
1.4
1.7
5.0
8.1
Av.
1.3
2.1
4.8
8.2
Max.
1.8
3.0
6.2
9.7
Min
1.1
1.7
3.5
7.1
Pacific Ocean (32°19.3'N 137°33.5'E; depth 4079m)
0
1.4
2.0
5.0
8.4
10
1.4
-
-
8.1
49
1.3
2.5
4.7
8.5
Search WWH ::
Custom Search