Tributyltin chloride determination

Temperature programming packed-capillary and open capillary HTLC-ICP-MS (up to 200 °C) has been reported [738]. //.HTLC-ICP-MS instrumental coupling has been applied to organotin (tetraethyltin, tributyltin chloride and triphenyltin chloride) and organolead (tetramethyllead and tetraethyllead) compounds [756]. HTLC-ICP-MS can be used for the determination of organometallic compounds at low concentrations. The observed limit of detection (LOD) was 5pg for Pb in... 

Laughlin et al. [122] analysed chloroform extracts of tributyltin dissolved in seawater using nuclear magnetic resonance spectroscopy. It was shown that an equilibrium mixture occurs which contains tributyltin chloride, tributyl tin hydroxide, the aquo complex, and a tributyltin carbonate species. Fluorometry has been used to determine triphenyltin compounds in seawater [123]. Triph-enyltin compounds in water at concentrations of 0.004-2 pmg/1 are readily extracted into toluene and can be determined by spectrofluorometric measurements of the triphenyltin-3-hydroxyflavone complex. 

Determination of Tributyltin Chloride in Marine and Fresh Waters by LSE and GC with ECD... 

The diastereomers 251/ewf-251 and 252/ent-252 could be separated and were decom-plexed separately. From the fraction of 251/ewt-251,253 was obtained with 85% ee (e.r. = 92.5 7.5), and the fraction of 252/ent-252 yielded ewt-253 with 88% ee (e.r. = 6 94). A similar situation results from the reaction with tributyltin chloride or alkylation reagents, but the diastereomeric ratio is strongly dependent on the electrophile. The following conclusion is drawn from these and further experiments The enantiomeric ratio is determined by a selection of the chiral base between the diastereotopic methylene groups, since the benzylic carbanionic centres are labile, whereas the diastereomeric ratio results from the relative rate of the electrophile approach syn or anti with respect to the A-methyl group. One question remains—why are opposite d.r. values formed in the alkylation by methyl iodide and ethyl iodide ... 

TBTO is a colorless liquid of low water solubility and low polarity. Its water solubility varies between <1.0 and >100 mg/L, depending on the pH, temperature, and presence of other anions. These other anions determine the speciation of tributyltin in natural waters. Thus, in sea water, TBT exists largely as hydroxide, chloride, and carbonate, the structures of which are given in Figure 8.5. At pH values below 7.0, the predominant forms are the chloride and the protonated hydroxide at pH8 they are the chloride, hydroxide, and carbonate and at pH values above 10 they are the hydroxide and the carbonate (EHC 116). 

An estimate of the accuracy of both analytical methods was performed on bis(tri-n-butyltin) oxide and tri-n-butyltin chloride solutions (8.9-35.6 ig/l) prepared in filtered (0.45 im) near-shore seawater free of detectable organ-otins. Average mean recoveries of 92.8% by both methods were determined for tributyltin standard solutions. Low ng/1 levels of mono-, di-, and tributyltin were found in samples taken from San Diego Bay. 

Tributyltin oxide and its metabolites were determined in urine after conversion to chlorides with HC1, extraction with ether containing tropolone (1), conversion to hydrides with NaBFLt, extraction with hexane and GC-AAS end-analysis LOD 1 pg/L for BuSnFL and Bu2SnH2, and 2 pg/L for Bu3SnH87b. 

Hydrolysis. NMR results show that TBT carboxylates undergo fast chemical exchange. Even the interfacial reaction between TBT carboxylates and chloride is shown to be extremely fast. The hydrolysis is thus not likely to be a rate determining step. Since the diffusivity of water in the matrix is expected to be much greater than that of TBTO, a hydrolytic equilibrium between the tributyltin carboxylate polymer and TBTO will always exist. As the mobile species produced diffuses out, the hydrolysis proceeds at a concentration-dependent rate. Godbee and Joy have developed a model to describe a similar situation in predicting the leacha-bility of radionuclides from cementitious grouts (15). Based on their equation, the rate of release of tin from the surface is ... 

Among these, carboxylic acid esters have gained importance in the field of wood preservation, because they are of lower volatility and water-solubility, but higher thermal stability than TBTO. From comparison data it can be concluded that the tributyltin (TBT) moiety of the TBT esters determines their antimicrobial effectiveness and also their oral toxicity. This is in line with the fact that the TBT esters tend to dissociated into the hydrated TBT cation and the respective anion. Due to the lower TBT content compared with TBTO greater quantities of TBT carboxylic acid ester therefore have to be used to achieve sufficient antimicrobial effectiveness. Hydrohalide acid esters of practical importance as microbicides have been tributyltin fluoride (19.6.6.) and triphenyltin chloride (19.6.7.). 

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