Biotransformation of tributyltin chloride in the presence of resting-cell suspensions of pure strains of microorganisms

We describe the degradation of tributyltin chloride by several strains of fungi, yeasts and bacteria under resting-cell conditions in phosphate buffer, with low initial concentrations of substrate. Yields of biotic conversion of tributyltin ranging from 10 to 77% were observed after a five-day incubation at 28°C. In most cases, dibutyltin and monobutyltin compounds and a fraction of volatile products were formed. Volatile tin compounds essentially included derivatives of monobutyltin and traces of other organomethyltins (mono-, di-, and trimethyltins; di- and tri-butyltins), probably as the corresponding organostannanes. Compared with conditions in which the substrate was incubated with growing microorganisms, higher yields of degradation and substantial amounts of volatile products were obtained.     

Simultaneous speciation of butyltin and phenyltin compounds in the waters of south-west Spain.

An analytical method for the simultaneous speciation of butylin and phenyltin compounds has been applied to a study of the water quality in six locations (rivers and sea) in South West Spain. It was not intended to provide a comprehensive survey of the area but to establish what the maximum levels might be for a subsequent and more detailed study. Phenyltin species were not found in any sample, however tributyltin was present (100-400 ng l-1) in the Cadiz Bay samples, which suggests that the biological water quality may sometimes be depressed. Wherever tributyltin was present, dibutyltin and monobutyltin occurred, possibly, as a result of a degradation process.     

Speciation of butyltin compounds by on-line HPLC-ETAA of tropolone complexes in environmental samples

Tropolone (Trop) forms in solution stable complexes with monobutyltin (MBT Trop₂) and dibutyltin (DBT Trop). This property has been used to develop a separation procedure of butyltin compounds by liquid chromatography on cyanopropyl-bonded silica columns with a solution of tropolone in toluene as eluent. Tin-specific detection by on-line ETAA allowed the development of a simple procedure suitable for the determination of tributyltin and dibutyltin in water and sediment samples.     

水相中丁基锡化合物同时衍生／萃取气相色谱／火焰光度检测方法研究

本文建立了水相中丁基锡化合物的衍生／萃取一步进行气相色谱／火焰光度检测的方法，探讨了溶剂，氮气流速，温度及火焰条件对分离及测定的影响，获得了理想的分离及检测条件。检出限分别为一丁基锡（ＭＢＴ）及二丁基锡（ＤＢＴ）０．２５ｎｇ，三丁基锡（ＴＢＴ）及四丁基锡（Ｂｕ４Ｓｎ）０．５ｎｇ；线性范围０－８ｎｇ，相对标准偏差小于４％。     

丁基锡系列化合物与脱氧核糖核酸的相互作用

通过紫外（ultraviolet,UV）光谱和圆二色（circular dichroism,CD）光谱,研究了丁基锡化合物（一丁基锡、二丁基锡和三丁基锡）与脱氧核糖核酸（deoxyribonucleic acid,DNA）的作用方式以及时间和浓度的影响。结果显示丁基锡化合物与DNA的作用是双重的,既作用于DNA的碱基,对双螺旋结构有一定影响,又作用于DNA的磷酸基团,使构象发生变化。但是,丁基锡化合物与脱氧核糖核酸作用的程度和方式与丁基锡种类、时间和浓度等因素有关。一丁基锡倾向于与磷酸基团作用,三丁基锡倾向于与碱基作用,而二丁基锡与两者作用程度相近。短时间内,丁基锡化合物的作用位点通常是DNA的碱基;长时间时,则作用位点往往是DNA的磷酸基团。低浓度的丁基锡化合物倾向与DNA的碱基结合,高浓度的丁基锡化合物倾向与DNA的磷酸基团结合。     

Plasma Membrane Perturbation Induced by Organotins on Erythrocytes from Salmo irideus Trout

Tributyltin chloride and its degradation products monobutyltin and dibutyltin act as water pollutants, owing to the use of tributyltin chloride as a biocide in marine paint formulations. These compounds are lipid-soluble and undergo bioaccumulation and bioconcentration. Salmo irideus trout erythrocytes were studied to evaluate the possible effects of these compounds on freshwater fish, which could be exposed to long-term effects due to bioaccumulation of organotins. Data showed that tributyltin increases the haemolysis rate, starting at 10 μM, while dibutyltin has a scant protective effect at each concentration tested. Similar studies were performed in the presence of carbon monoxide (CO), which is protective against membrane oxidative stress due to haemoglobin (Hb) auto-oxidation. In these conditions all the organotins tested induced an increase in the haemolysis rate. These results suggest that the consequence of auto-oxidation of Hb could condition the effects of some organotin compounds. Steady-state fluorescence of probes embedded in the lipidic part of the membrane was used to evaluate the modifications induced by organotins to the physico-chemical state of phospholipids.     

Gas chromatography-high-resolution mass spectrometry based method for the simultaneous determination of nine organotin compounds in water,sediment and tissue

A GC-HRMS based method for the accurate and sensitive determination of nine organotin compounds, tetrabutyltin (TeBT), tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT), monophenyltin (MPhT), tricyclohexyltin (TCyT), and dicyclohexyltin (DCyT) in sediment, tissue and water samples is presented and discussed. Mass spectral features of these analytes via both low resolution quadrupole and high resolution magnetic sector, GC-HRMS conditions under selective ion monitoring mode and QA/QC criteria for the positive identification of analyte are all provided. Linearity of response and minimal detectable limits are illustrated for each of the nine compounds monitored and the estimates of method limits-of-detection were 7-29 ppt for water and 0.35-1.45 ppb for tissue or sediments. Sample preparation considerations and precision are discussed for spiked water and sediment samples, whereas method accuracy was established by analysing a certified reference material (CRM) mussel sample and comparing our results to the assigned values. Good agreement was found between our results and assigned or indicative values for MBT, DBT, TBT, DPhT and TPhT (cyclohexyl-tins were not present in the CRM).     

Analysis of Organotin Compounds via a Thermabeam® LC–MS Interface

Selected organotin compounds, relating to antifouling paints, have been analysed using a particle beam interface system designed for use on liquid chromatography–mass spectrometry (LC–MS) instruments. The resultant mass spectra matched those obtained from conventional electron-impact (EI) techniques, and consistent data over several injections and different elution times were obtained. Data obtained from tributyltin, dibutyltin, monobutyltin, triphenyltin and diphenyltin (each as the chlorides) are presented. This interface has been shown to maintain sample and therefore spectral integrity for these compounds and is of potential use in further investigations relating to organotin environmental pollution.     

Effect of organotin compounds on trout AMP‐deaminases

The comparative toxicity of the organotin compounds tributyltin chloride (TBTC), dibutylin dichloride (DBTC) and monobutyltin trichloride (MBTC) was investigated on 5′ adenylic acid deaminase (AMP‐deaminase) purified from trout skeletal muscle and heart. Treatment with TBTC of both enzymatic forms of AMP‐deaminase rapidly decreases the enzyme activity, and the organotin derivatives DBTC and MBTC have a significant minor inhibitory effect. Differences were observed in TBTC inhibition rate between trout muscle and heart purified enzymes that could be related to the different cellular localization of the two AMP‐deaminases. Copyright © 2001 John Wiley & Sons, Ltd.     

The Effect of Organotin Compounds on the Permeability of Model Biological Membranes

The efflux of dimethylarsinic acid (DMA) from liposomes formed from egg phosphatidylcholine (EPC) is increased when tributyltin chloride (TBT) is added to the extraliposomal compartment; however the addition of monobutyltin trichloride (MBT) slows down the efflux. When the liposomes are prepared from EPC and organotin compounds, different mechanisms for DMA efflux seem to operate: TBT–EPC liposomes show a mixture of facilitated and passive diffusion; MBT–EPC liposomes show only passive diffusion. The facilitated diffusion of DMA⁻ seems to be stopped by the addition of TBT to the extraliposomal compartment. © 1997 by John Wiley & Sons, Ltd.     

Determination of butyltin and phenyltin species by reversed-phase liquid chromatography and fluorimetric detection

Chromatographic separation of monobutyltin (MBT), monophenyltin (MPhT), dibutyltin (DBT), diphenyltin (DPhT), tributyltin (TBT) and triphenyltin (TPhT) was studied using end-capped reversed-phases (RP) and methanol-acetic acid-water or acetronitrile-acetic acid-water mixtures as mobile phases. Several RP columns were evaluated, and the effect of acetic acid, oxalic acid, triethylamine, and organic modifier on peak shape and retention was examined. A method based on gradient elution RPLC and fluorimetric detection is proposed for the determination of DBT, DPhT, TBT and TPhT. The sensitivity of the method makes it suitable for environmental analysis.     

Isotope dilution analysis as a definitive tool for the speciation of organotin compounds

Different spike solutions available for the determination of butyltin compounds by isotope dilution analysis are described and applied for the determination of butyltin compounds in PACS-2 certified reference material. Additionally, those spike solutions were evaluated during the course of an interlaboratory exercise organised by the National Research Council of Canada and the Laboratory of the Government Chemist (UK) in order to quantify tributyltin in a pilot sediment. The aim of this project was to evaluate the capabilities of isotope dilution mass spectrometry to reduce the uncertainty in the certification of Reference Materials for the speciation of organotin compounds. All participants were supplied with a 17Sn-enriched TBT solution from the Laboratory of the Government Chemist (UK). In our case, we performed the analysis of the pilot sediment also using a 119Sn enriched spike (mixed mono-, di- and tributyltin) and a 118Sn-119Sn double spike. The use of these additional spike solutions not only allowed the determination of monobutyltin and dibutyltin in the pilot sediment but also the evaluation and correction of possible extraction-derived rearrangement reactions. An excellent agreement amongst our results and between the participants was obtained with a precision of 8.4% RSD at a level of ca. 80 ng TBT g(-1) (as Sn).     

Selective preconcentration and determination of tributyltin in fresh water by electrothermal atomic absorption spectrometry

A rapid and simple method for separation and determination of tributyltin (TBT) in mineral and tap water is described. The procedure is based on the selective retention of TBT by a chelating resin, Amberlite XAD-2 impregnated with tropolone. The addition of 0.8% sulfuric acid to the water sample leads to the retention of TBT by the resin while monobutyltin (MBT), dibutyltin (DBT) and inorganic tin remain in solution. TBT is eluted with methyl isobutyl ketone (MIBK) obtaining a preconcentration factor of 80. Tin concentration is determined by ETAAS using zirconium coated tubes. Multi-injection and hot injection techniques are used in order to enhance the sensitivity of the method. A detection limit of 14.4 ng L(-1) is achieved with recoveries near to 100%. The procedure has been successfully applied to TBT determination in various fresh water samples.     

Simultaneous determination of monomethylmercury, monobutyltin, dibutyltin and tributyltin in environmental samples by multi-elemental-species-specific isotope dilution analysis using electron ionisation GC-MS

In this work, the simultaneous determination of four organometallic species (monomethylmercury, monobutyltin, dibutyltin and tributyltin) in environmental samples by using a GC-MS system with electron ionisation has been established. The measurement of isotope ratios in each species was accomplished by selecting the most adequate molecular cluster, and simple mathematical equations were applied to correct the contributions of 13C from the organic groups attached to the tin and mercury atoms. The influence of different parameters such as dwell time on the precision and accuracy of the measured isotope ratios in each target species has also been studied. The determination and the sample preparation procedures presented in this work were first individually validated by analysing several certified reference materials for butyltin compounds (mussel tissue CRM-477 and marine sediment SOPH-1) and for monomethylmercury (tuna fish CRM-464) using an innovative focused microwave technology for the extraction of the species from the solid samples. Additionally, the simultaneous determination of the four species was successfully validated by obtaining quantitative recoveries in spiked natural waters and by analysing the certified reference material BCR-710 (certified in tributyltin and monomethylmercury). The values obtained in such certified tissue were fully in agreement not only with the certified mass fractions but also with the proposed indicative values for mono- and dibutyltin.     

Acid/extraction treatment of bivalves for organotin speciation

A method is described for leaching of nanogram amounts of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPT), diphenyltin (DPT), triphenyltin (TPT), and monomethyltin (MMT) from bivalves. The procedure is based on soaking the samples in a water-hydrogen bromide mixture (1:1) with magnetic stirring for 30 min followed by extraction with a 0.04% (w/v) tropolone solution in dichloromethane for 2 h. Organotins are determined by GC-FPD after clean-up through a Florisil column and fat hydrolysis by 1mol/L NaOH, followed by derivatization through Grignard pentylation. The method has been applied for an investigation of the occurrence of organotins in bivalves in south-west Spain. Received: 3 September 1994 / Revised: 2 October 1996 / Accepted: 7 November 1996     

DNA damage induced by organotins on ­trout‐nucleated erythrocytes

The effect of tributyltin‐chloride (TBTC), dibutyltin‐chloride (DBTC) and monobutyltin‐chloride (MBTC) on rainbow trout (Salmo irideus) nuclear DNA, was investigated by means of single cell gel electrophoresis (‘comet’ assay). Our data show that TBTC presents a marked genotoxic effect, whereas the genotoxic effect is less pronounced for DBTC and it is completely absent for MBTC. These results could be important in evaluating the environmental risks deriving from the use of these molecules as a antifouling agents in marine paints and as agricultural biocides. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations:

TBTC,

tributyltin‐chloride;

DBTC,

dibutyltin‐chloride;

MBTC,

monobutyltin‐chloride;

Hb,

hemoglobin.

     

HPTLC analysis of organotin compounds in preservative solutions and preservative-treated wood

A high-performance thin-layer chromatographic (HPTLC) method is described for the determination of tributyltin compounds (bis(tri-n-butyltin) oxide, TBTO, and tri-n-butyltin naphthenate, TBTN) and their degradation products (dibutyltin and monobutyltin compounds). The organotin compounds are extracted from wood with ethanol containing 0.5% (v/v) of hydrochloric acid and the separation of the defferent kinds of organotin compounds is achieved by thin-layer chromatography. The sample spots are measured using a scanning densitometer after decomposing the organotin compounds to inorganic tin by ultraviolet irradiation and visualization of the spots with pyrocatechol violet. Applications of the method to detection and quantification of organotin compounds in preservative solutions, in recently impregnated wood, and in wood samples from five-year-old window frames are described.     

丁基锡化合物与人血清白蛋白相互作用的研究

通过紫外、荧光和CD光谱, 研究了船体防污漆中主要防污成分——三丁基锡(TBT)化合物及其降解产物——一丁基锡(MBT)和二丁基锡(DBT)与人血清白蛋白(HSA)相互作用的方式与程度, 考察了浓度、酸度、有机溶剂和离子强度等因素对相互作用的影响. 结果表明, 丁基锡与HSA的相互作用是双重的, 既有丁基锡中锡离子与HSA的配位作用, 又有丁基锡中丁基基团的疏水作用, 导致HSA二级结构破坏, α-螺旋结构减少和构象转变. 一般情况下, MBT以配位作用为主, TBT以疏水作用为主, DBT两者兼而有之.     

Comparison of Derivatization Methods for the Determination of Butyl- and Phenyl-tin Compounds in Mussels by Gas Chromatography

Two different derivatization methods, alkylation with Grignard reagents, and ethylation with sodium tetraethylborate, were compared for the determination of organotin compounds, viz. tributyltin, dibutyltin, monobutyltin, triphenyltin, diphenyltin and monophenyltin, in mussel samples. Temperature, reaction time and concentration of Grignard reagents were optimized in the former method; in the latter the effect of pH, concentration of sodium tetraethylborate and reaction time were studied. In the derivatization with Grignard reagents hexyl, pentyl, propyl, ethyl and methyl were used as alkyl Grignard groups. A critical evaluation of the different derivatization methods is presented. © 1997 John Wiley & Sons, Ltd.     

A fast and effective routine method based on HS-SPME–GC–MS/MS for the analysis of organotin compounds in biota samples

This work validated an automated, fast, and low solvent- consuming methodology suited for routine analysis of tributyltin (TBT) and degradation products (dibutyltin, DBT; monobutyltin, MBT) in biota samples. The method was based on the headspace solid-phase microextraction methodology (HS-SPME), coupled with gas chromatographic separation and tandem mass-spectrometry (GC–MS/MS). The effectiveness of the matrix-matched signal ratio external calibration was tested for quantification purposes. The exclusion of matrix influences in the calibration curves proved the suitability of this versatile quantification method. The method detection limits obtained were of 3 ng Sn g⁻¹ dw for all the analytes. The analysis of references materials showed satisfying accuracy under optimum calibration conditions (% recovery between 87–111%; |Z-scores|<2). The repeatability RSD% and intra-laboratory reproducibility RSD% were lower than 9.6% and 12.6%, respectively. The work proved the remarkable analytical performances of the method and its high potential for routine application in monitoring organotin compounds (OTC).