8.3.2
Mercury
Inorganic Elements
211
Uthe et al. [617] have described a rapid semi-micro method for determining methylmercury in crustacea. The procedure involves extracting the methylmercury into
toluene as methylmercury(II) bromide, partitioning the bromide into aqueous ethanol as the thiosulphate complex, re-extracting methylmercury(II) iodide into benzene, followed by gas chromatography on a glass column (4 ft x 0.25 in.) packed with
7 % of Carbowax 20M on Chromosorb Wand operated at 170°C with nitrogen as
carrier gas (60 ml min-I) and electron capture detection. Down to O.Oll!g kg-I of
methylmercury in a 2 g sample could be detected. A comparison of the results with
those obtained by atomic absorption (total Hg content) indicated that all the fish
samples examined contained more than 41 % of the mercury as methylmercury.
8.3.3
Tin
Han and Weber [618] studied the speciation of methyl- and butyltin compounds and
inorganic tin in oysters by hydride generation atomic absorption spectrometry. Recoveries from spiked samples of oyster tissue were about 100 % and no organotin
decomposition products were observed. Detection limits of inorganic tin were, respectively, 0.023, 0.025, and O.Olll!g kg-I oyster sample (wet weight). A comparative
study of monomethyltin levels in shellfish from the Great Bay Estuary, N. H. and the
Mediterranean Sea (Turkish coast) suggested that monomethyltin in Great Bay oysters was a result of biological methylation of inorganic tin, whereas, in the Mediterranean Sea, mono- and dimethyltin compounds resulted from degradation of anthropogenic trimethyltin. Comparisons were also made ofbutyltin levels in oysters from the
Great Bay Estuary and English shellfish samples.
Jones [745] carried out speciation studies of methyl- and butyltin compounds and
inorganic tin using hydride generation atomic absorption spectometry. Down to 0.01
to 0.02 mg kg-I organotin compounds could be determined.
8.4
Inorganic Elements
8.4.1
Iodine
Fassett and Murphy [746] used isotope dilution laser resonance ionization mass
spectrometry to determine iodine in oysters at the mg kg-I level. Rao and Chatt [747]
employed neutron activation analyses of microwave acid digests of oyster samples to
determine iodine.
Mercury
Inorganic Elements
211
Uthe et al. [617] have described a rapid semi-micro method for determining methylmercury in crustacea. The procedure involves extracting the methylmercury into
toluene as methylmercury(II) bromide, partitioning the bromide into aqueous ethanol as the thiosulphate complex, re-extracting methylmercury(II) iodide into benzene, followed by gas chromatography on a glass column (4 ft x 0.25 in.) packed with
7 % of Carbowax 20M on Chromosorb Wand operated at 170°C with nitrogen as
carrier gas (60 ml min-I) and electron capture detection. Down to O.Oll!g kg-I of
methylmercury in a 2 g sample could be detected. A comparison of the results with
those obtained by atomic absorption (total Hg content) indicated that all the fish
samples examined contained more than 41 % of the mercury as methylmercury.
8.3.3
Tin
Han and Weber [618] studied the speciation of methyl- and butyltin compounds and
inorganic tin in oysters by hydride generation atomic absorption spectrometry. Recoveries from spiked samples of oyster tissue were about 100 % and no organotin
decomposition products were observed. Detection limits of inorganic tin were, respectively, 0.023, 0.025, and O.Olll!g kg-I oyster sample (wet weight). A comparative
study of monomethyltin levels in shellfish from the Great Bay Estuary, N. H. and the
Mediterranean Sea (Turkish coast) suggested that monomethyltin in Great Bay oysters was a result of biological methylation of inorganic tin, whereas, in the Mediterranean Sea, mono- and dimethyltin compounds resulted from degradation of anthropogenic trimethyltin. Comparisons were also made ofbutyltin levels in oysters from the
Great Bay Estuary and English shellfish samples.
Jones [745] carried out speciation studies of methyl- and butyltin compounds and
inorganic tin using hydride generation atomic absorption spectometry. Down to 0.01
to 0.02 mg kg-I organotin compounds could be determined.
8.4
Inorganic Elements
8.4.1
Iodine
Fassett and Murphy [746] used isotope dilution laser resonance ionization mass
spectrometry to determine iodine in oysters at the mg kg-I level. Rao and Chatt [747]
employed neutron activation analyses of microwave acid digests of oyster samples to
determine iodine.