274
P.J. Craig· S.N. Forster· R.O. Jenkins· D.P. Miller· N.Ostah . L.M. Smith· T.-A. Morris
fully applied to the analysis of organoantimony compounds by Giirleyiik et al. (1997).
Detection limits were found to be in the order of 15 pg Sb.
14.2.4.5
Liquid Chromatography
Lintschinger et al. (1997) have produced effective separation of antimony(V) and
organoantimony [as (CH3hSbCl2 and (CH3hSb(OHhl with an anion exchange high
performance liquid chromatography (HPLC) column under alkaline conditions and
a complexing reagent in the mobile phase. Element specific detection was obtained
using a flame atomic absorption system which produced a detection limit in the
mg t' range, or alternatively when using ICP-MS as the detector system, the detection
limit was in the j.1g t' range. A more recent paper published by Lintschinger et al. (1999)
reported improvements on the anion exchange HPLC-ICP-MS technique, with a
detection limit of 5 ng t' , achieved mainly by avoiding contamination from chromatographic devices. Andrewes et al. (1998), have used Alumina-B SPE cartridges rinsed
with ammonium carbonate buffer (50 mM, pH l2) to remove most of the inorganic antimony(III) from a medium. This allowed detection with HG-GC-AAS and
HG-GC-ICP-MS of the organoantimony compounds present in much smaller quantities, which previously would have been hidden by a broad tail of SbH 3 in the chromatograms.
14.2.5
Conclusion
All of the analytical instruments described above are reproducible and reliable techniques used for the analysis and speciation of antimony compounds. The availability
of this wide range of techniques leaves the choice of systems utilized at the discretion
of the analytical laboratory concerned, whereby, the most appropriate integrated series of techniques to be used is dependent upon cost, availability, efficiency and/or
sensitivity.
14.3
Microbial Biotransformation of Antimony Compounds
14.3.1
Biomethylation of Antimony
The term biomethylation is used to describe the process mediated by living organisms in which methyl groups are transferred to various metals or metalloids. Many
elements of environmental importance undergo biomethylation, including As, Hg, Sn,
Se, Te, Ge, Sb, P, S, CI and Pb. Several biological methylating agents are known, the most
important of which are S-adenosylmethionine and methylcobalamine. S-adenosylmethionine has been described as 'the ubiquitous methylating agent' and has been the
most extensively studied of all methylating agents. It has been established that Sadenosylmethionine is a methylating agent for arsenic (Cullen et al. 1977) and selenium (Takahashi et al. 1990), and it is thought to be involved in the methylation of tel-
P.J. Craig· S.N. Forster· R.O. Jenkins· D.P. Miller· N.Ostah . L.M. Smith· T.-A. Morris
fully applied to the analysis of organoantimony compounds by Giirleyiik et al. (1997).
Detection limits were found to be in the order of 15 pg Sb.
14.2.4.5
Liquid Chromatography
Lintschinger et al. (1997) have produced effective separation of antimony(V) and
organoantimony [as (CH3hSbCl2 and (CH3hSb(OHhl with an anion exchange high
performance liquid chromatography (HPLC) column under alkaline conditions and
a complexing reagent in the mobile phase. Element specific detection was obtained
using a flame atomic absorption system which produced a detection limit in the
mg t' range, or alternatively when using ICP-MS as the detector system, the detection
limit was in the j.1g t' range. A more recent paper published by Lintschinger et al. (1999)
reported improvements on the anion exchange HPLC-ICP-MS technique, with a
detection limit of 5 ng t' , achieved mainly by avoiding contamination from chromatographic devices. Andrewes et al. (1998), have used Alumina-B SPE cartridges rinsed
with ammonium carbonate buffer (50 mM, pH l2) to remove most of the inorganic antimony(III) from a medium. This allowed detection with HG-GC-AAS and
HG-GC-ICP-MS of the organoantimony compounds present in much smaller quantities, which previously would have been hidden by a broad tail of SbH 3 in the chromatograms.
14.2.5
Conclusion
All of the analytical instruments described above are reproducible and reliable techniques used for the analysis and speciation of antimony compounds. The availability
of this wide range of techniques leaves the choice of systems utilized at the discretion
of the analytical laboratory concerned, whereby, the most appropriate integrated series of techniques to be used is dependent upon cost, availability, efficiency and/or
sensitivity.
14.3
Microbial Biotransformation of Antimony Compounds
14.3.1
Biomethylation of Antimony
The term biomethylation is used to describe the process mediated by living organisms in which methyl groups are transferred to various metals or metalloids. Many
elements of environmental importance undergo biomethylation, including As, Hg, Sn,
Se, Te, Ge, Sb, P, S, CI and Pb. Several biological methylating agents are known, the most
important of which are S-adenosylmethionine and methylcobalamine. S-adenosylmethionine has been described as 'the ubiquitous methylating agent' and has been the
most extensively studied of all methylating agents. It has been established that Sadenosylmethionine is a methylating agent for arsenic (Cullen et al. 1977) and selenium (Takahashi et al. 1990), and it is thought to be involved in the methylation of tel-