Determinations organotin compounds

Tropospheric Ozone The Environmental Chemistry of Organotin Compounds Determination of Heavy Metals in Sewage Sludge Inorganic Deposits in Invertebrate Tissues. 

For example, octahedral quadrupole splitting observed for the cis-octahedral analogs 7,8). More recently, temperature-dependent Mossbauer measurements have been used in conjunction with Raman spectroscopy to determine molecular weights 453) and lattice rigidity 460) of various organotin compounds. 

At present, it is reported that there is no analytical technique capable of quantifying the entire organotin compound with its associated ligand in dilute solutions in water (Parametrix, 2002g), although experimental procedures are under development that may allow for determination of the entire organotin compormd in water (e.g. Yoder, 2003). 

Arakawa Y, Wada O, Manabe M (1983) Extraction and fluoro-metric determination of organotin compounds with Morin. Analytical Chemistry, 55 1901 -1904. 

Tutschku S, Mothes S, Dittrich K (1994) Determination and speciation of organotin compounds by gas chromatography-microwave induced plasma atomic emission spectrometry. Journal of Chromatography A, 683 269-276. 

Takeuchi M, Mizuishi K, Hobo T (2000) Determination of organotin compounds in environmental samples. Analytical Sciences, 16 349-359 (http //wwwsoc.nii.ac.jp/cgi-bin/jsac/analsci/pdf/16/4/349/ accessed 27 June 2003). 

Bayona JM (1995) Development of supercritical fluid extraction procedures for the determination of organotin compounds in sediment. In Quevauviller Ph, Maier EA, and Griepink B, eds. Quality assurance for environmental analysis, pp 465-487. Elsevier, Amsterdam. 

Potentiometric titration procedures with sodium methoxide have been reported for non-sulfur-containing organotin compounds in solvent extracts of polymers, and for phenolic antioxidants with sodium isopropox-ide in pyridine medium [21]. Organotin compounds in solvent extracts of PVC can be determined by potentiometric and manual titration procedures [487,488]. 

The methods which have been used to determine the configurational stability of organotin compounds and those which have successfully been applied to synthesize such optically active molecules are reviewed, including the chromatographic resolution of racemic mixtures. 

Organotin compounds with diastereotopic groups can be used to determine how rapidly tin inverts its configuration. This is shown below if a racemic mixture M + M is examined by NMR, two distinct signals are expected for the diastereo-... 

It is therefore possible to determine the configurational stability at tin by looking at the NMR spectrum of a racemic mixture of suitably substituted organotin compounds of type M (see figure 1) bearing diastereotopie groups. Some of the compounds examined by this elegant method are listed in Table 1. 

The optical purity of almost all the organotin compounds described in this chapter is not yet known. In order to determine the stereoselectivity of substitution reactions at the tin atom of these organotin compounds, it is almost always necessary to know the optical purity of the starting compound and of the final product. The method described in this section can be used not only for the resolution of racemic organotin compounds but also for the determination of their optical purity 50). It will be a valuable tool for the determination of the stereoselectivity of the reactions described in Chapter 5, and of other reactions which will be studied. 

Nasielsky 17) discussed both the static and dynamic stereochemistry of some organotin compounds and showed that pentacoordination is the dominant factor determining the physical and chemical properties of these compounds. 

Brinckmann [570] used a gas chromographic method with or without hydride derivatisation for determining volatile organotin compounds (e.g., tetram-ethyltin) in seawater. For nonvolatile organotin compounds a direct liquid... 

To determine organotin compounds in amounts down to 1 - 5 ng/1, McAvoy et al. [ 129] ethylated the seawater, isolated organotin solid-phase micro extraction and determined it by micro capillary GCMS. 

Luskima and Syavtsillo [120] have described a spectrophotometric procedure utilising phenylfluorone for the determination of organotin compounds in water. 

A method for the determination of organotin compounds by anodic stripping polarography has been published [121]. It has yet to be applied to seawater. Since the sensitivity permits the measurement of 0.01 ppm of the tin compounds, it is likely to be not quite sensitive enough for seawater and would require a preconcentration step. 

The conditions for reliable cyclic voltametry determination of trace Sn concentrations in sea water were investigated. All organotin compounds should be converted to Sn(II) by UV-photolysis adsorption on mercury drop in the presence of 40 pM of tropolone (1) cyclic voltametry stripping shows two cathodic peaks, corresponding to the two-step process Sn(IV) — Sn(II) -> Sn(0)29. A complex of Sn ions with catechol can be accumulated in a glassy carbon mercury film electrode, followed by stripping voltametry measurement in the cathodic direction, at pH 4.2-4.7. Interference occurs when Cu, Cd and Cr are present LOD 0.5 pg/L for 300 s accumulation30. 

A sensitive determination of organotin compounds in sediments is based on separation of the chlorides R SnCl4- , n = 1-3, R = Me, n-Bu, Ph, by GC-FPD or GC-ECD using a DB-608 open tubular column with HC1 doping of the carrier gas LOD 30 ng Sn/g of sediment77. A modification of this method uses GC-FPD with DB-1 capillary column and a 611.5 nm filter. The column requires special pretreatment with an HBr/EtOAc solution78. 

TABLE 8. Structural determination of organotin compounds by X-ray crystallography... 

The radioactive tin-125 isotope in the bis(tributyltin-125) oxide enabled Klotzer and Gomer40 to use a neutron activation analysis to determine the percent tin in the organotin compounds formed in the photochemical reaction between bis(tributyltin-125) oxide and glucose (equation 39). 

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