Emission to air of volatile organotins from tributyltin‐contaminated harbour sediments

An analytical method for determining the presence in air of volatile forms (e.g. chlorides) of tributyltin (TBT) and that of methylbutyltins Me _nBu_(4?n)Sn (n = 1–3) was developed and used to establish whether dredged harbour sediments contaminated with TBT served as sources of air pollution with respect to organotin compounds. The method was based on active sampling of the air being analysed and sorption of analytes onto Poropak‐N. Sorbed methylbutyltins were extracted with dichloromethane and analysed by gas chromatography using flame photometric detection. Other butyltins were converted into butyltin hydrides prior to analysis by gas chromatography. It was shown that TBT‐contaminated sediments from Marsamxett Harbour, Malta, placed in 0.5 l chambers through which air was displaced by continuous pumping for 11 days released mainly methylbutyltins, with concentrations (as tin) reaching maximum 48 h mean values of 8.7 (Me₃BuSn), 22.1 (Me₂Bu₂Sn) and 93.0 ng m^?3(MeBu₃Sn) being measured. Other volatile forms of TBT, dibutyltin and monobutyltin were detected in the headspace air, but very infrequently and at much lower tin concentrations (<2 ng m^?3). It was also shown that methylbutyltins dissolved in sea‐water ([Sn] = 0.2 to 400 ng l^?1) were very difficult to exsolve from this medium, even on prolonged evaporation of the solutions using mechanical agitation and active ventilation. The results suggest that emission of methylbutyltins from contaminated sediments probably occurs only from the surface of the material. The environmental implications of these findings in the management of TBT‐polluted harbour sediments are discussed. Copyright © 2002 John Wiley & Sons, Ltd.     

Certification of mono-, di-, and tributyltin compounds in marine sediment certified reference material by species-specific isotope dilution mass spectrometric analysis using synthesized <Superscript>118</Superscript>Sn-labeled butyltins

A new marine sediment reference material (NMIJ CRM 7301-a) for butyltins analysis was prepared and certified by the National Metrological Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). The original material of the sediment was collected at a bay near industrial activities in Japan. The sediment material was air-dried, sieved, homogenized, and packaged into 1,000 glass bottles (60 g each). Certification of NMIJ CRM 7301-a was carried out at NMIJ using two different types of species-specific isotope dilution mass spectrometry: isotope dilution–ethylation–gas chromatography/inductively coupled plasma mass spectrometry (GC/ICPMS) and isotope dilution–ethylation–gas chromatography/mass spectrometry (GC/MS). A mixture of ¹¹⁸Sn-enriched monobutyltin, dibutyltin, and tributyltin was synthesized in our laboratory and was used as a spike for both techniques. Certified values are given for tributyltin (0.044±0.004 mg kg^–1 as Sn), dibutyltin (0.056±0.006 mg kg^–1 as Sn, and monobutyltin (0.058±0.013 mg kg^–1 as Sn), being at lower levels than currently available sediment CRMs for the analysis of organotins.     

Contamination of outdoor settled dust by butyltins in Malta

The presence of compounds of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) was determined in outdoor settled dust collected from several sites on the island of Malta, mainly from flat rooftops of school buildings. The dust was separated into three size fractions with diameters (µm) > 250, 125–250 and < 125, and the two finer fractions were analysed for butyltins using extraction with glacial acetic acid followed by derivatization/solvent extraction with sodium tetraethylborate in the presence of iso‐octane and quantitation by gas chromatography with flame photometric detection. The presence of TBT, DBT and MBT was established in most of the samples and TBT concentrations varied from non‐detectable (<5 ng Sn g^?1) to highs of 15.5 and 18.7 µg Sn g^?1 in Senglea and Marsaxlokk. TBT was generally found at concentrations significantly higher than reported hitherto in house dust collected from European homes. The geographical distribution of total organotins in both dust fractions suggests that TBT originates mainly from antifouling marine paint residues which contaminate the urban environment when ships' hulls are sand‐ or hydro‐blasted during maintenance and repair at the drydocks facility in Grand Harbour. Other significant sources of TBT are located at Marsaxlokk fishing port and Wied i?‐?urrieq creek, both hosting sizeable communities of fishermen and leisure boating. The data also suggest that the municipal solid waste landfill at Maghtab is an inland source of butyltins. We suggest that dust containing harmful butyltins could possibly be ingested to expose humans to a risk which is probably of concern especially for young children living close to the hotspots of contamination. Copyright © 2007 John Wiley & Sons, Ltd.     

Butyltin compounds in severn sound,lake huron,canada

Severn Sound is a heavily used recreational and beating area in the southeast corner of Georgian Bay, Lake Huron, Canada. Because of the concern over the possible release of tributyltin species (TBT) from antifouling paints on boat hulls and marinas, surveys were carried out in 1989 and 1992 to determine the presence of this species and its degradation products dibutyltin (DBT) and monobutyltin (MBT) in this area. Many fish (pike and young–of–the–year spottail shiners) and sediment samples collected in 1989 contained detectable levels of TBT. A maximum concentration of TBT was recorded in northern pike in the spring to be 240 ng Sn g^?1. Maximum levels occurred in marinas during the beginning of the boating season and significantly reduced during the summer and early autumn, although the maximum value of TBT in sediment (392 ng Sn g^?1) was observed in the summer of 1989. The seasonal variation of TBT levels was further substantiated in the subsequent 1992 study, in which sediments from three areas in a marina were sampled at monthly intervals from May to October. TBT levels were much higher in May and then generally decreased with time. Mussels (Elliptio complanta) caged in the marina for three months also contained TBT. DBT was frequently detected in the sediments but less frequently in fish and mussels. MBT was generally below detection limits. Plants (macrophytes and cladophora) contained very small amounts of butyltin compounds.     

Electrochemical speciation of organotin compounds in water and sediments. Application to sea water after ion-exchange separation

For the quantitative speciation of tributyltin, Bu₃Sn⁺ (TBT), in the presence of dibutyltin, Bu₂Sn²⁺ (DBT), monobutyltin, BuSn³⁺ (MBT), triphenyltin, Ph₃Sn⁺ (TPT), and inorganic tin in water samples and sediments, an accurate, reproducible, simple and rapid electrochemical method was developed. After extraction of the organotin compounds with dichloromethane, TBT could be selectively determined as species by alternating current polarography directly in the organic phase without any derivatisation. The successful application of this technique could be proved by the results obtained by intercomparison exercises on TBT in water samples and sediments, organized by the Community Bureau of Reference (BCR). For the application of this technique to sea water samples a preliminary ion exchange separation of TBT from the major components of sea water was performed, achieving a detection limit for TBT in the ppt range.     

Hepatic butyltin concentrations in beluga whales (Delphinapterus leucas) from the St Lawrence Estuary and northern Quebec,Canada

Butyltin (tributyltin TBT; dibutyltin DBT and monobutyltin MBT) speciation was measured in the liver of beluga whales from the St Lawrence Estuary and Hudson Strait (northern Quebec). Using GC–MS, liver samples were analysed from 21 beluga whales found dead, stranded along the shores of the St Lawrence during the period 1995–1998. In all cases, including a neonate specimen, the liver was contaminated with butyltin compounds with concentrations in the range 0.04–2.1 mg Sn kg⁻¹ on a dry weight basis. Liver samples of five beluga whales from Hudson Strait obtained in the summer of 1998 were also analysed. For these animals, hepatic butyltin concentrations were consistently below the detection limit (<0.5 ng Sn g⁻¹ for MBT and <0.2 ng Sn g⁻¹ for DBT and TBT). Compared with published data on the contamination by TBT of the marine mammals of the St Lawrence in 1988, these contemporary results clearly indicate that the level of contamination of the beluga whales in this coastal marine ecosystem has not decreased ten years after regulating the use of TBT‐based antifoulants on small craft. Copyright © 2000 John Wiley & Sons, Ltd.     

Toxicity andaccumulation of tributyltin chloride on tilapia

Acute toxicity (96 h) and bioconcentration experiments of tributyltin chloride (TBT) in tilapia were conducted in an aqueous solution with salinity of 15‰, and a toxicity mechanism has been suggested. The 96-h LC₅₀ was 3.80 μg Sn l⁻¹. Bioconcentration factors in different tissues increased in the order muscle<gill<viscera. Studies on the metabolism of TBT showed that it can be easily degraded to DBT (dibutyltin) in these tissues. Further degradation of DBT to MBT (monobutyltin) was much more difficult. A mesocosm was used for the first time to study the toxicity of TBT in tilapia. The result demonstrated that the TBT bioconcentration curve changed with the initial concentrations of TBT but the order of bioconcentration in the tissues did not change. © 1998 John Wiley & Sons, Ltd.     

Occurrence of butyltin compounds in marine sediments and bivalves from three harbour areas (Saigon,Da Nang and Hai Phong) in Vietnam

A survey of organotin compounds comprising tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in sediment and clam (Meretrix meretrix) was undertaken in Vietnam in 2003. Samples were collected from dry docks and cargo harbours in Ho Chi Minh (south), Da Nang (centre) and Hai Phong (north) cities. Measurable amounts of TBT, DBT and MBT were found in all samples. The total concentration of the butyltin compounds (ΣBTs) in sediment from shipyards and vessel repair yards (Nam Trieu, Song Cam, Lach Tray and Ba Son) were always higher than those measured in cargo ports (Hai Phong, Da Nang, and Sai Gon). The highest ΣBTs concentration (as tin: 122 ng g^?1 dry wt) was found in the sediment from Song Cam station, where seven shipyards are located. The lowest concentrations of ΣBTs occurred in sediments from the Da Nang and Hai Phong cargo ports (as tin: 21–22 ng g^?1 dry wt). This implies that the major source of BTs in the marine environment in Vietnam is from the shipbuilding activities. The ratio of TBT to Σ(MBT + DBT) in sediment was 0.67 ± 0.03 for all the sampling sites, indicating the recent use of TBT in Vietnam. For the clam (M. meretrix), the concentration of ΣBTs (as tin) varied in the range 11.2–60.1 ng g^?1 wet wt. There was a good correlation (R² = 0.85) between total organic matter‐normalized ΣBTs in sediment and hexane‐extractable organic matter‐normalized ΣBTs in clam soft tissue. The mean biota–sediment accumulation factors (organic carbon/lipid) for MBT, DBT and TBT in clam's soft tissue were found to be 1.83 ± 0.66, 1.44 ± 0.23 and 1.16 ± 0.47 respectively, indicating that sediment‐bound BTs might be an important source of contamination for the clam. Copyright © 2005 John Wiley & Sons, Ltd.     

Selective non-chromatographic determination of tributyltin in sediments using EDTA and diphenylcarbazone as masking agent

Two analytical procedures based on the generation of volatile tributyltin derivatives, their separation by headspace solid-phase microextraction (HS SPME) and subsequent determination using plasma optical emission spectrometry (OES) have been developed for the selective determination of trace tributyltin (TBT) in the presence of other butyltins and inorganic tin in sediments without the use of chromatography. A microwave-assisted leaching of tin compounds from the sediment using 25%_v/v acetic acid is applied for sample pretreatment. The first method takes advantage of TBT chloride releasing from the lecheate after adding 3 M hydrochloric acid, and subsequent separation of the analyte by HS SPME using Carboxen-poly(dimethylsiloxane) (CAR/PDMS). The second method involves the use of masking agents, namely ethylenediaminetetraacetic acid (EDTA) and diphenylcarbazone (DFC), which form stable chelates with monobutyltin (MBT) and dibutyltin (DBT), respectively, followed by the ethylation of tributyltin at pH 5 using sodium tetraethylborate (NaBEt4) solution. The final concentration of NaBEt4 is 0.05%_w/v. The parameters affecting the TBT derivatisation and separation by HS SPME have been optimised including the selection of SPME fibre coating (PDMS, CAR/PDMS), the amount of masking agents and NaBEt4 added, sorption time (2–40 min) and sorption temperature (25–60°C). Higher sensitivity and robustness are attained with the method involving ethylation derivatisation, leading to the limit of detection (LOD) of 3 ng L^?1. The selective release of TBT is observed from aqueous solutions, where the concentrations of MBT and DBT were in 2–50-fold excess to TBT. The SPME-TD-MIP-OES methods have been validated against several certified reference materials (CRMs), including SOPH-1 marine sediment, PACS-2 marine sediment and BCR 646 freshwater sediment.     

Speciation of Organotin Compounds by Capillary Electrophoresis Coupled with Hydride Generation Atomic Fluorescence Spectrometry

Abstract

Capillary electrophoresis (CE) coupled with hydride generation atomic fluorescence spectrometry (HG‐AFS) was developed for the speciation analysis of organotin compounds. The four organotin cations of trimethyltin (TMT), monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were completely separated by CE in a 50 cm×75 µm i.d. fused‐silica capillary at 15 kV and using a mixture of 50 mmol l^?1 H₃BO₃?50 mmol l^?1 Tris‐5% v/v methanol (pH 7.10) as electrolyte. 0.008 mmol l^?1 cetyltrimethylammonium bromide (CTAB) added to the electrolyte suppressed the adsorption of the organotin cations on the inner wall of capillary. The generated hydride species were detected on‐line with AFS. The precisions (RSD, n=5) were in the range of 1.7–3.1% for migration time and 3.8–4.7% for peak area response for the four organotin species. The detection limits ranged from 1–10 µmol l^?1 (as Sn).     

Simultaneous butyltin determinations in the microlayer,water column and sediment of a northern Chesapeake Bay marina and receiving system

Butyltins were determined in the microlayer, water column and sediment of a northern Chesapeake Bay marina and its receiving system. Concentrations of the toxicant species tributyltin (TBT) ranged from 60 to 4130 ng dm⁻³ in the microlayer, from 34 to 367 ng dm⁻³ in the water column and from <0.05 to 1.4 m̈g g⁻¹ (dry weight) in sediment. TBT concentrations in all three environmental compartments were higher in the marinas than in the receiving system. Concentrations of TBT in the microlayer and water column of the study area were potentially toxic to sensitive aquatic biota. The microlayer appears to be depleted in dibutyltin relative to tributyltin compared to both water column and sediment.     

Degradation of dibutyltin in sea water by pyoverdins isolated from Pseudomonas chlororaphis

The yellow compounds pyoverdins were isolated from Pseudomonas chlororaphis, which was isolated from mud in Japan. Degradation of tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) by pyoverdin (20 mg) was carried in sea water (30 ml) containing a 6 µg l^?1 concentration of TBT, DBT, and MBT at 24 °C for 24 h in aerobic conditions. TBT, DBT, and MBT in sea water were analyzed by gas chromatography–mass spectrometry in selected ion monitoring mode. DBT in sea water was degraded to MBT by pyoverdins isolated from P. chlororaphis. However, TBT and MBT in sea water was not degraded by pyoverdins. The optimum degradation of DBT in sea water was at pH 4.8–8.2, at a temperature 25–30 °C. Copyright © 2002 John Wiley & Sons, Ltd.     

Speciation of butyltins in fish and sediment by means of gas chromatography with flame photometric detection

A modified method for the determination of tributyl-, dibutyl-, and monobutyl-tin in fish and sediment samples is proposed. The samples are digested with hydrochloric acid and the butyltin compounds are extracted into a tropolone solution in pentane and pentylated by a Grignard reaction. The products are cleaned up by washing with a sodium hyrdoxide solution, dried over sodium sulphate, concentrated by evaporation and analysed by gas chromatography with flame photometric detection, using an interence filter at 610 nm. Problems peculiar to the fish and sediment samples are overcome by this improved clean-up procedure. The limit of detection for tributyltin in fish is 0.04 m?g g^?1 and the reproducibility at 0.06 μg g^?1, expressed as the relative standard deviation, is 6.8%. Contaminated sediment samples were found to contain the mixed methylbutyl-tin compounds Me₂BuSn⁺ and MeBu₂Sn⁺.     

Optimization of GC-ICPMS system parameters for the determination of butyltin compounds in Hungarian freshwater origin sediment and mussel samples

The optimization and application of gas chromatograph coupled with inductively coupled plasma mass spectrometer (GC-ICPMS) (equipped with a commercially available interface) for the speciation of butyltin compounds in freshwater origin sediment and mussel samples is described. Optimization focused on the system parameters that have the greatest effect on signal intensity such as plasma power, ion lenses and make up gas flow (in the interface). Xenon (Xe) containing argon gas (Ar) was applied as tuning gas providing continuous Xe signal for the optimization of system parameters. It was found that plasma power and make up gas are interrelated variables and provide a set of paired optimum values at each power settings. The absolute optimum values obtained at 800 W plasma power and 1.2 L min⁻¹ make up gas flow rate when 7 mm sample depth was adjusted. The optimum settings obtained were then checked by means of a test solution (tetraethyltin dissolved in hexane). Same optimum conditions were found when tin (Sn) transient signals were monitored. Detection limits were calculated for the three species using the optimized system parameters. Detection limits are the following: for monobutyltin (MBT) 5.6 ng Sn kg⁻¹, for dibutyltin (DBT) 6.6 ng Sn kg⁻¹ and for tributyltin (TBT) 3.4 ng Sn kg⁻¹ obtained. Determination of the butyltin compounds were carried out by means of species-specific isotope dilution analysis. The spike solution contained all species investigated but with altered isotopic composition. Each species were enriched in their ¹¹⁹Sn isotope. Concentrations found in Hungarian freshwater origin mussel and sediment samples ranged between 19 and 39 ng g⁻¹for MBT, between 1.2 and 6.3 ng g⁻¹ for DBT and between 1.2 and 3.2 ng g⁻¹ for TBT indicated as Sn in dry weight. Validation of the method was done by means of certified reference materials (BCR CRM 646 and 477). Good agreement was found between certified and experimental values. Normalized deviation (E_n) was also computed in order to validate the method used. E_n values obtained ranged between 0.07 and 0.11 for mussel samples and between 0.26 and 0.72 for sediment samples. These values show that isotope dilution-GC-ICPMS methodology is valid for the determination of MBT, DBT and TBT from both types of matrices.     

Voltammetric speciation of butyltin compounds

A sensitive and selective procedure for the determination of tributyltin chloride (TBT), dibutyltin dichloride (DBT) and monobutyltin trichloride (MBT) based on solid phase extraction (SPE) with ENVI-Carb non-porous carbon as column material followed by adsorptive cathodic stripping voltammetry (AdSV) in the presence of tropolone is reported. The determination limits achieved using a 500 mL water sample were 210 ng L^–1 (as Sn) for TBT, 30 ng L^–1 (as Sn) for DBT and 40 ng L^–1 (as Sn) for MBT. The method was used to determine the levels of butyltin species in surface water from the yacht harbour at Zewen on the Mosel River and in the tap water supply in Trier.Dedicated to Professor Dr. K. Doerffel and Professor Dr. H. Kriegsmann on the occasion of their 70th birthdays     

Search for triorganotins along the Mar del Plata (Argentina) marine coast: finding of tributyltin in egg capsules of a snail Adelomelon brasiliana (Lamarck, 1822) population showing imposex effects

Cases of imposex were clearly identified in Adelomelon brasiliana living in the Mar del Plata (Argentina) coastal area; percentages as high as 50.0% were determined among the samples studied. These were the first reported cases of ocurrence of imposex in this type of gastropod. Since this is one of the known tributyltin (TBTs) effects, and no previous reports of determination of TBTs in gastropods eggs were found, methods were developed for the speciation and quantitative determination of organotins in A. brasiliana egg capsules. Determination of organotins in samples collected in the Mar del Plata area showed contents of tributyltin chloride (TBT) as high as 400 ng l^?1 in water and 6.50 µg g^?1 in sediments of areas of intensive boat traffic. The results showed the presence of TBT in the egg capsules of A. brasiliana at three different instars (range 0.264–1.86 µg per egg). As far as we know, this is the first report of the finding of TBT in gastropod egg capsules. Copyright © 2004 John Wiley & Sons, Ltd.     

Measurement of butyltin contamination of water and sediment in Osaka Bay,Japan

The concentration of tributyltin (TBT) in surface water from Osaka Bay ranged from 0.023 to 0.061 µg l⁻¹ in 1989 and from not detected (ND) to 0.059 µg l⁻¹ in 1990 while the proportion of TBT as a percentage of the total butyltins (BTs) was more than 40%. The concentration of TBT was also surveyed in the Port of Osaka and the Yodo River basin. TBT levels were highest in the estuary (the Port of Osaka), followed by sea areas (Osaka Bay) and rivers (Yodo River basin). A fairly high correlation coefficient between TBT concentration and salinity in water from the estuary and the sea areas was observed. This result shows that the TBT in the estuary water is diluted by seawater. Generally, the TBT concentrations in the water columns were distributed uniformly and the composition of the BTs was also constant. TBT was detected in sediment from Osaka Bay in the range from ND to 0.023 mg kg⁻¹ dry weight with a high ratio of monobutyltin (MBT) to the total BTs. TBT in sediment core was also measured; its concentration decreased with core depth. It was estimated from these measurements that the release of TBT into Osaka Bay began in the 1960s. Copyright © 1998 John Wiley & Sons, Ltd.     

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.     

Optimization of butyltin measurements for seawater,tissue, and marine sediment samples

Optimized techniques for measuring butyltins at the sub-part-per-trillion (ppb; 1:10¹²) level in seawater and at the part-per-billion (ppb; 1:10⁹) level in tissues and sediments are presented. Purge and trap/hydride derivatization followed by atomic absorption (AA) detection was optimized to give better sensitivity than was previously attained for seawater, yielding environmental detection limits of 0.08–0.2 ng dm^?3. Improvement in precision and reproducibility in measurement of butyltins in tissues and sediments was attained by adjustment of the concentration in an organic extract to minimize matrix effects and by use of internal standards. The tissues and sediments were homogenized and extracted with methylene chloride (CH₂Cl₂) after acidification. The butyltins in the organic layer were derivatized with hexylmagnesium bromide and analyzed by gas chromatography (GC) with a flame photometric detector (FPD). The absolute detection limits in tissues and sedimets were 0.1 ng for tributyltin (TBT), 0.12 ng for dibutyltin (DBT) and 0.29 ng for monobutyltin (MBT).     

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).