Metals
179
Good agreement was obtained by this procedure in determinations of selenium in
NBS reference SRM 1577 oyster tissue, for which a value of 2.26 ± 0.24 mg kg-I was
obtained against a certified value of 2.1 ± 0.5 mg kg-I.
Maher [549] has reported on selenium levels in prawn (4.01 mg kg-I) and scallop
(1.24 mg kg-I), and has pointed out that the selenium is predominantly associated
with soluble protein and not present as inorganic selenium.
8.7.1
Tin
Thin mm anodic stripping voltammetry has been applied to the determination of tin
in distillates of sulphuric acid-hydrobromic acid digests of marine organisms
[550].
8.7.8
Vanadium
Blotcky et al. [551] have described a pre-irradiation chemistry neutron activation
analysis procedure employing cation-exchange chromatography for the determination of trace-level vanadium in marine biological specimens, including shrimps crabs
and oysters. The procedure, utilizing a low-power nuclear reactor (1 x 1011 n cm- 2 s- I ),
consists of wet digestion of the sample with concentrated nitric acid at 65 °e, cation
exchange chromatography employing nitric acid wash to remove the major radioactivatable contaminants (sodium and chloride ions), ammonium hydroxide elution to
remove vanadium from the resin, and neutron irradiation and radioassay for S2V. The
limit of detection of the method is 30 J.Lg kg-I.
Table 8.3
Analyses of marine biologicals in the Galveston Island area for vanadium a (mg kg-I)
(from [557])
4 moll-I NH 4 0H NH 4 0H elutions
eluent b
yield, %
White shrimpc Bolivar
0.64 ± 0.06 d
77
East beach
2.05 ± 0.06
79
Sportsman Road
1.41 ± 0.09
88
San Luis Pass
0.28 ± 0.07
68
Blue crabe Bolivar
0.62 ± 0.04
64
East Beach
1.00 ± 0.08
70
Sportsman Road
0.84 ± 0.03
88
San Luis Pass
0.84 ± 0.06
63
Oyster + Bolivar
0.65 ± 0.11
81
East Beach
0.43 ± 0.13
90
Sportsman Road
0.62 ± 0.02
76
San Luis Pass
0.45 ± 0.05
94
a n =6
b The sum of two 3 m 4 moll-I NH 4 0H elutions
C Penaeus setiferous
d All values expressed in I1S V per g of dry weight sample
e Collinectes sapidus
f Crassostrea virginica
Residue
0.78 ± O.13 d
0.61 ± 0.18
1.64 ± 0.25
0.12 ± 0.04
0.47 ± 0.05
0.76 ± 0.18
1.00 ± 0.12
0.47 ± 0.07
0.18 ± 0.12
0.26 ± 0.18
0.80 ± 0.06
0.07 ± 0.05
Total V content
1.42 ± 0.19 d
2.67 ± 0.18
3.05 ± 0.34
0.40 ± 0.09
1.09 ± 0.09
1.76 ± 0.26
1.84 ± 0.14
1.31 ± 0.09
0.83 ± 0.02
0.68 ± 0.24
1.42 ± 0.05
0.53 ±.0.03
179
Good agreement was obtained by this procedure in determinations of selenium in
NBS reference SRM 1577 oyster tissue, for which a value of 2.26 ± 0.24 mg kg-I was
obtained against a certified value of 2.1 ± 0.5 mg kg-I.
Maher [549] has reported on selenium levels in prawn (4.01 mg kg-I) and scallop
(1.24 mg kg-I), and has pointed out that the selenium is predominantly associated
with soluble protein and not present as inorganic selenium.
8.7.1
Tin
Thin mm anodic stripping voltammetry has been applied to the determination of tin
in distillates of sulphuric acid-hydrobromic acid digests of marine organisms
[550].
8.7.8
Vanadium
Blotcky et al. [551] have described a pre-irradiation chemistry neutron activation
analysis procedure employing cation-exchange chromatography for the determination of trace-level vanadium in marine biological specimens, including shrimps crabs
and oysters. The procedure, utilizing a low-power nuclear reactor (1 x 1011 n cm- 2 s- I ),
consists of wet digestion of the sample with concentrated nitric acid at 65 °e, cation
exchange chromatography employing nitric acid wash to remove the major radioactivatable contaminants (sodium and chloride ions), ammonium hydroxide elution to
remove vanadium from the resin, and neutron irradiation and radioassay for S2V. The
limit of detection of the method is 30 J.Lg kg-I.
Table 8.3
Analyses of marine biologicals in the Galveston Island area for vanadium a (mg kg-I)
(from [557])
4 moll-I NH 4 0H NH 4 0H elutions
eluent b
yield, %
White shrimpc Bolivar
0.64 ± 0.06 d
77
East beach
2.05 ± 0.06
79
Sportsman Road
1.41 ± 0.09
88
San Luis Pass
0.28 ± 0.07
68
Blue crabe Bolivar
0.62 ± 0.04
64
East Beach
1.00 ± 0.08
70
Sportsman Road
0.84 ± 0.03
88
San Luis Pass
0.84 ± 0.06
63
Oyster + Bolivar
0.65 ± 0.11
81
East Beach
0.43 ± 0.13
90
Sportsman Road
0.62 ± 0.02
76
San Luis Pass
0.45 ± 0.05
94
a n =6
b The sum of two 3 m 4 moll-I NH 4 0H elutions
C Penaeus setiferous
d All values expressed in I1S V per g of dry weight sample
e Collinectes sapidus
f Crassostrea virginica
Residue
0.78 ± O.13 d
0.61 ± 0.18
1.64 ± 0.25
0.12 ± 0.04
0.47 ± 0.05
0.76 ± 0.18
1.00 ± 0.12
0.47 ± 0.07
0.18 ± 0.12
0.26 ± 0.18
0.80 ± 0.06
0.07 ± 0.05
Total V content
1.42 ± 0.19 d
2.67 ± 0.18
3.05 ± 0.34
0.40 ± 0.09
1.09 ± 0.09
1.76 ± 0.26
1.84 ± 0.14
1.31 ± 0.09
0.83 ± 0.02
0.68 ± 0.24
1.42 ± 0.05
0.53 ±.0.03