Table 3

Abundance of six forms of Se in sequential extraction fractions of the bulk sample (in μg/g) and fraction of each form of Se in three coals (in %)


Bituminous coal
Anthracite
Cokeite


Content (μg/g)
Fraction (%)
Content (μg/g)
Fraction (%)
Content (μg/g)
Fraction (%)

Water-leachable
ND
0.00
0.063
3.23
0.057
3.45
Ion-exchangeable
0.128
4.66
0.138
7.14
0.186
11.3
Organic matter-bound
1.08
39.1
0.219
11.3
ND
0.00
Carbonate-bound
0.093
3.36
0.224
11.6
0.245
14.9
Sulfide-bound
0.581
21.1
0.975
50.4
0.895
54.5
Silicate-bound
0.875
31.8
0.316
16.4
0.259
15.8
Total
2.76
100
1.93
100
1.64
100
Bulk coal (μg/g)
4.00
2.43
2.00
Recovery (%)
68.9
79.5
82.1

Abbreviation: ND, not detected

Zhang et al. Geochemical Transactions 2007 8:14   doi:10.1186/1467-4866-8-14