230
R. Barbieri et aJ.
istry, University of Padua, possibly suggested by their head A. Miolati (see e.g. the study
on organotins, Riccoboni 1937); a number of papers in the field were successively published by L. Riccoboni, G. Tagliavini and their co-workers (Tagliavini et al. 1962, Barbieri
et al. 1958). U. Croatto introduced Mossbauer spectroscopy at the Institute of General
Chemistry, University of Padua, around 1960, as a consequence of a scientific tour in
Germany; a homemade spectrometer was built, according to Croatto's design, which
allowed the beginning of studies in the field. Lastly, the research actually effected in
Palermo on the interaction of nucleic acids, and their constituents, with metal derivatives originates from the thesis of R. Barbieri, the supervisor being A. Turco (Barbieri
1956; Cessi and Turco 1956).]
12.2
Analysis and Speciation of Organotins in the Environment
Analytical methods and procedures for the determination of organotin(IV) derivatives
in biological and environmental systems have been amply reported and discussed in a
series of papers and review articles (Miller and Craig 1998, Maguire 1991, Maguire 1987).
Mossbauer spectroscopy, 119Sn, has been employed in the "in vitro" speciation of
tributyltin(IV) and triphenyltin(IV) derivatives spiked to estuarine sediments (Eng
et al. 1986; Lucero et al. 1992; May et al. 1994; Whalen et al. 1993) mainly in view of the
large use of triorganotins in antifouling coating of ship hulls (Kjaer 1992). The field
has been reviewed, in relation also with environmental and biological aspects (May
et al. 1993). The determined 119Sn Mossbauer parameters (; (isomer shift) and tlE
(nuclear quadrupole splitting) are summarized in Table 12.1.
The procedure employed for the obtainment of absorber samples to be submitted
to 119Sn Mossbauer investigation was as follows (Lucero et al. 1992; Whalen et al. 1993;
May et al. 1994):
i. Sediment samples (defined as anaerobic, anoxic) were collected from selected sites
in bays and estuaries, and kept frozen until employed.
ii. Aerobic (oxic) samples were prepared by air-drying part of a given anoxic sample,
and grinding.
iii. "Sediment spiking" was effected by adding solid R3SnX (e.g. 3.30/0 w/w) to oxic and
anoxic sediment samples (e.g. 5 g), covering the mixture with, e.g. 5-100 ml of synthetic sea water, and shaking in the dark at room temperature for about one week;
the mixture was left in the dark for an additional two weeks. The pH of synthetic sea
water, as well as other solution characteristics such as salinity, were adjusted before
addition to the R 3 SnX spiked sediments.
Comparison of the 119Sn Mossbauer parameters of the "in vitro" systems described
above, with data related to solid state triorganotins, Table 12.1, yielded the following
conclusions:
i. nBu3SnF and (nBu3SnhS04: limited, or null, interaction with both oxic and anoxic
sediments; the same holds for nBu3Sn(02CCH3) in oxic sediments (May et a1.1994).
ii. nBu3SnCI and nBu3Sn(02CCH3) interact with anoxic sediments in different ways in
relation to the origin of the sediment (May et al. 1994).
R. Barbieri et aJ.
istry, University of Padua, possibly suggested by their head A. Miolati (see e.g. the study
on organotins, Riccoboni 1937); a number of papers in the field were successively published by L. Riccoboni, G. Tagliavini and their co-workers (Tagliavini et al. 1962, Barbieri
et al. 1958). U. Croatto introduced Mossbauer spectroscopy at the Institute of General
Chemistry, University of Padua, around 1960, as a consequence of a scientific tour in
Germany; a homemade spectrometer was built, according to Croatto's design, which
allowed the beginning of studies in the field. Lastly, the research actually effected in
Palermo on the interaction of nucleic acids, and their constituents, with metal derivatives originates from the thesis of R. Barbieri, the supervisor being A. Turco (Barbieri
1956; Cessi and Turco 1956).]
12.2
Analysis and Speciation of Organotins in the Environment
Analytical methods and procedures for the determination of organotin(IV) derivatives
in biological and environmental systems have been amply reported and discussed in a
series of papers and review articles (Miller and Craig 1998, Maguire 1991, Maguire 1987).
Mossbauer spectroscopy, 119Sn, has been employed in the "in vitro" speciation of
tributyltin(IV) and triphenyltin(IV) derivatives spiked to estuarine sediments (Eng
et al. 1986; Lucero et al. 1992; May et al. 1994; Whalen et al. 1993) mainly in view of the
large use of triorganotins in antifouling coating of ship hulls (Kjaer 1992). The field
has been reviewed, in relation also with environmental and biological aspects (May
et al. 1993). The determined 119Sn Mossbauer parameters (; (isomer shift) and tlE
(nuclear quadrupole splitting) are summarized in Table 12.1.
The procedure employed for the obtainment of absorber samples to be submitted
to 119Sn Mossbauer investigation was as follows (Lucero et al. 1992; Whalen et al. 1993;
May et al. 1994):
i. Sediment samples (defined as anaerobic, anoxic) were collected from selected sites
in bays and estuaries, and kept frozen until employed.
ii. Aerobic (oxic) samples were prepared by air-drying part of a given anoxic sample,
and grinding.
iii. "Sediment spiking" was effected by adding solid R3SnX (e.g. 3.30/0 w/w) to oxic and
anoxic sediment samples (e.g. 5 g), covering the mixture with, e.g. 5-100 ml of synthetic sea water, and shaking in the dark at room temperature for about one week;
the mixture was left in the dark for an additional two weeks. The pH of synthetic sea
water, as well as other solution characteristics such as salinity, were adjusted before
addition to the R 3 SnX spiked sediments.
Comparison of the 119Sn Mossbauer parameters of the "in vitro" systems described
above, with data related to solid state triorganotins, Table 12.1, yielded the following
conclusions:
i. nBu3SnF and (nBu3SnhS04: limited, or null, interaction with both oxic and anoxic
sediments; the same holds for nBu3Sn(02CCH3) in oxic sediments (May et a1.1994).
ii. nBu3SnCI and nBu3Sn(02CCH3) interact with anoxic sediments in different ways in
relation to the origin of the sediment (May et al. 1994).