Tin - Toxicology of Metals - page 821

et al ., 1998; Quevauviller et al ., 1995) have described the
major analytical methods for the determination of orga-
notin species. Most techniques are based on separation
by gas chromatography (GC). Organotin compounds
are mostly analyzed after extraction or digestion with
either the Grignard method (e.g., derivatization with
pentylmagnesium bromide) or the ethylborate method
(Rudel, 2003). The resulting derivatives from both
methods are volatile and can be analyzed by the GC
method with atomic emission (GC-AES) or mass spec-
trometry detection (GC-MS). Methods for detection
of phenyltin using GH and electron capture detector
(ECD) were reported (Soderquist et al ., 1974). Use of an
electrothermal quartz furnace for atomic absorption can
increase the effi ciency for determination of methylated
tin in water (Chau et al ., 1982). An analytical method
published by Muller (1987) allows simultaneous meas-
urement of 19 organotin compounds by capillary GC
and fl ame photometric detection (FPD). HPLC is also
widely used for analysis of organotin species (Astruc
et al ., 1990). However, there is a risk of degradation for
butytin on reversed phase material, and that resulted
in modifi cation of new procedures involving HPLC
and ID-ICP-MS (isotope dilution ICP-MS) (Brown
et al ., 1994). It has been used successfully for the deter-
mination of di- and tributyltin in sediment and mus-
sel (Brown et al ., 1994) and represents a very promising
analytical method for tin speciation. Besides that, after
HPLC separation, tin can be analyzed by fl ame, quartz
furnace, or electrothermal AAS, increasing the effi -
ciency of tin determination (Astruc et al ., 1989). Clas-
sical fl ame AAS is now of less interest because of its
very low sensitivity (Leroy et al ., 1998). An application
of inductively coupled plasma atomic emission after
HPLC increases the residence time of the analyte in
the plasma, thereby lowering the detection limits
(Lafreniere et al ., 1987). Coupling HPLC with AAS or
inductively coupled plasma atomic emission increased
the effi ciency and enabled the continuous measurement
(Leroy et al ., 1998). The electron capture detector (ECD)
is another classical technique for detection of di- and
trialkyltin chlorides, triphenyltin, and tricyclohexyltin.
Other recent techniques, which have gained impor-
tance, are microwave-induced plasma atomic emission
spectrometry and mass spectrometry coupled to cap-
illary GC (Leroy et al ., 1998). Differential pulse anodic
stripping voltammetry (DPASV) has been applied for
detection of dibutyltin chloride in water (Kitamura
et al ., 1984). The detection limit is in the range of 10 −4 -10 −6
mol/L (Leroy et al ., 1998). Instrumental neutron activa-
tion analysis has also been used for determination of
tin; however, the disadvantages of this method are lim-
ited availability, analysis, and very high cost (Hirano
et al ., 2001). Moreover, some basic analytical problems

remain to be solved for reliable speciation with HPLC.
These include absorption in the column packing, col-
umn or buffer solutions competing and displacing bio-
inorganic ligands, and incomplete separation.
Despite the considerable number of techniques
with high effi ciency for determination of organotin
and total tin, there is not a recognized standard proce-
dure as yet. This has resulted in enormous scattering
of values and inability to compare data from different
sources. Moreover, reliable methods have still to be
developed for the quantitative extraction, separation,
and determination of many individual tin species in
mixtures containing both inorganic tin and organotin
compounds that may occur in various media. There-
fore, two main approaches may be used to provide
validation or useful complementary information: the
use of certifi ed reference materials and the use of alter-
native different principles-based methods.

3 PRODUCTION AND USES

3.1 Production
The earth's crust contains approximately 2-3 mg/kg
tin, which comprises 0.0006% of earth's crust (Buda-
vari, 2001). Annual world production in 1990 of tin was
approximately 225,000 tons, 70% of which is obtained
from the ores and 30% being recovered from the scrap
metal. The world's largest producer of tin in 2001 was
China (36% of the world total). Metallic tin is derived
from the mineral cassiterite (SnO 2 ) and to a lesser extent
from the sulfi de ore stannite (Cu 2 S-FeS-SnS 2 ) (Graf,
1996). Most of the world supply of tin, mainly as cassiter-
ite, comes from China, Indonesia, Peru, Brazil, Bolivia,
and Australia. The largest world producers of recycled
tin are France and the United States. Approximately
25,000 million food cans are produced in Europe each
year, and approximately 20% of them have unlacquered
tin-coated steel bodies (Blunden and Wallace, 2003).
Organometallic tin compounds have been used in
increasing amounts since 1950 for a variety of applica-
tions, and the annual world production has risen from
<50 tons in 1950 to approximately 50,000 tons in 1994
(Fent, 1996a). The annual world production of biocide
triorganotins is in the range of 8000-10,000 metric tons:
70% corresponding to tributyltin and triphenyltin
derivatives. Worldwide synthesis of tributyltin com-
pounds is approximately 9000 metric tons annually for
all applications (Laughlin et al ., 1986).

3.2 Uses
Tin is used in tin-plated containers, in solders, alloys
such as bronzes, babbit, pewter, and in more specialized