Organometallic compounds in non-saline sediments 177
Furthermore, ethylation facilities identification of organotin derivatives in the gas chromatogram, as the order of elution follows increasing degrees of substitution, which is
not the case of hexylated products.
Lobinski et al [27] speciated organotin compounds in sediment samples by
capillary gas chromatography using helium microwave induced plasma emission spectrometry as a detector. They used the procedure to determine mono-, di-, tri- and some
tetralkylated tin compounds in sediments. The ionic tin compounds were extracted
as diethyldithiocarbamates into pentane then converted to pentyl magnesium bromide
derivatives prior to gas chromatography. The absolute detection limit was 0.05 pg tin.
Gilmour et al [28] determined pictogram quantities of methyltins in sediments
as their hydride derivatives (methylstannanes) using gas chromatography-quadrupole
mass spectrometry. Hydride derivatives were prepared by addition of sodium borohydride in a closed, flow-through system. Borate buffer was added to the samples and
hydrogen generated from the borohydride which resulted in high purge efficiencies
for mono-di- and tri-methyltin. Selected ion monitoring with the mass spectrometer
allowed detection limits of 3–5 pg as tin for methyltins. Detection limits for 5 g sediment
sample were below pg tin g
−1 levels with a standard deviation of 6–18% depending
on the methyltin species and the sample type.
Szpunar et al [29] and Prange and Jensen et al [30] have determined organotin
species by using gas chromatography with indirectly coupled plasma mass spectrometric detection. In one study, butyltin species were extracted from sediments and
biomaterials in only 1–5 minutes by using microwave digestion [80]. In another
investigation, detection limits of ∼50 (Sn), 100 (Pb) and 120 fg (Hg) were achieved.
Various other workers have discussed the application of gas chromatography
to the determination of organotin compounds in non-saline sediments [31–37] high
performance liquid chromatography.
Yang et al [38] accomplished speciation of organotin compounds using reversephase liquid chromatography with inductively coupled plasma mass spectrometric
detection. The separation was complete in 6 minutes and detection limits were in
the range of 2.8–16 pg of tin for various species.
High-performance liquid chromatography coupled with fluorescence detection
[39, 40] or ion-exchange high-performance liquid chromatography with detection by
graphite furnace atomic absorption spectroscopy [41] proved to be sensitive methods,
but have limitations in separation power and ease of identification of unknown
products.
Eplor et al [42] used laser enhanced ionisation as a selective detector for the liquid
chromatographic determination of alkyltin compounds in sediments. The analysis was
performed on a 1-butanol extract of the sediment.
Miscellaneous
Other procedures have been used in studies of the occurrence of organotin compounds in sediments include supercritical fluid chromatography [44] atomic absorption
spectrometry [45] electrochemical methods [46], fluorimetric analysis [47] and X-ray
absorption near-edge structure spectrometry [48].
Takahashi et al [48] have developed a direct method for the speciation of tin
compounds in sold environmental samples by X-ray absorption near-edge structure
Furthermore, ethylation facilities identification of organotin derivatives in the gas chromatogram, as the order of elution follows increasing degrees of substitution, which is
not the case of hexylated products.
Lobinski et al [27] speciated organotin compounds in sediment samples by
capillary gas chromatography using helium microwave induced plasma emission spectrometry as a detector. They used the procedure to determine mono-, di-, tri- and some
tetralkylated tin compounds in sediments. The ionic tin compounds were extracted
as diethyldithiocarbamates into pentane then converted to pentyl magnesium bromide
derivatives prior to gas chromatography. The absolute detection limit was 0.05 pg tin.
Gilmour et al [28] determined pictogram quantities of methyltins in sediments
as their hydride derivatives (methylstannanes) using gas chromatography-quadrupole
mass spectrometry. Hydride derivatives were prepared by addition of sodium borohydride in a closed, flow-through system. Borate buffer was added to the samples and
hydrogen generated from the borohydride which resulted in high purge efficiencies
for mono-di- and tri-methyltin. Selected ion monitoring with the mass spectrometer
allowed detection limits of 3–5 pg as tin for methyltins. Detection limits for 5 g sediment
sample were below pg tin g
−1 levels with a standard deviation of 6–18% depending
on the methyltin species and the sample type.
Szpunar et al [29] and Prange and Jensen et al [30] have determined organotin
species by using gas chromatography with indirectly coupled plasma mass spectrometric detection. In one study, butyltin species were extracted from sediments and
biomaterials in only 1–5 minutes by using microwave digestion [80]. In another
investigation, detection limits of ∼50 (Sn), 100 (Pb) and 120 fg (Hg) were achieved.
Various other workers have discussed the application of gas chromatography
to the determination of organotin compounds in non-saline sediments [31–37] high
performance liquid chromatography.
Yang et al [38] accomplished speciation of organotin compounds using reversephase liquid chromatography with inductively coupled plasma mass spectrometric
detection. The separation was complete in 6 minutes and detection limits were in
the range of 2.8–16 pg of tin for various species.
High-performance liquid chromatography coupled with fluorescence detection
[39, 40] or ion-exchange high-performance liquid chromatography with detection by
graphite furnace atomic absorption spectroscopy [41] proved to be sensitive methods,
but have limitations in separation power and ease of identification of unknown
products.
Eplor et al [42] used laser enhanced ionisation as a selective detector for the liquid
chromatographic determination of alkyltin compounds in sediments. The analysis was
performed on a 1-butanol extract of the sediment.
Miscellaneous
Other procedures have been used in studies of the occurrence of organotin compounds in sediments include supercritical fluid chromatography [44] atomic absorption
spectrometry [45] electrochemical methods [46], fluorimetric analysis [47] and X-ray
absorption near-edge structure spectrometry [48].
Takahashi et al [48] have developed a direct method for the speciation of tin
compounds in sold environmental samples by X-ray absorption near-edge structure