Butyltin Compounds In Sediments Research Articles

Environmental matrices effect in butyltin determinations by GC/MS

The present study evaluated the matrix effect associated to determination of butyltin compounds (tripropyltin (TPrT), tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT)) in sediment and mussel tissues using derivatization by Grignard reaction and quantification by gas chromatography coupled mass spectrometry (GC-MS). A non-negligible matrix effect was verified for sediments (54.2, 20.3, 13.6 and -53.6 %) and mussel tissues (-12.5, -32.0, 59.4 and 65.7 %) for TPrT, TBT, DBT and MBT respectively. However, this matrix effect was prevailed by preparing the analytical curves using standard addition techniques. Thus, an analytical method was optimized and validated for a more accurate and precise determination of butyltin compounds in sediment and mussel tissue samples.

Butyltin compounds in sediment and biota from the lagoon of Bizerte (northern Tunisia): Potential risk for consumers?

ABSTRACTLevels of butyltins (BTs) were monitored in sediment samples and in seven fish species (Boops boops, Diplodus sargus, Sarpa salpa, Serranus scriba, Spicara smaris, Trachurus draco, and Trachinus mediterraneus), five bivalve species (Cerastoderma glaucum, Chlamys flexuosa, Mytilus galloprovincialis, Pinna nobilis, and Ruditapes decussatus), two gastropod species (Bolinus brandaris and Hexaplex trunculus), cuttlefish (Sepia officinalis), and shrimp (Penaeus notialis), most of which are commonly consumed in Tunisia. Samples were collected from Bizerte lagoon during March 2012. Average concentrations of total BTs found in sediment and the muscle of fishes, bivalves, gastropods, cuttlefish, and shrimp were 17.7, 11.5, 31.8, 36.9, 8.1, and 9.4 ng Sn g−1 dw, respectively. The calculation of tolerable average residue levels and non-cancer hazard quotient for tributyltin (TBT) showed that daily exposure of these seafood to TBT is unlikely to cause any deleterious effects to humans, thus indicating that consumers may not be at risk through the inclusion of these species in their regular diet.

Critical evaluation of various extraction procedures for the speciation of butyltin compounds in sediments

The efficiency of different extraction procedures for the simultaneous determination of butyltin compounds in marine sediments by gas chromatography–mass spectrometry (GC--MS) was critically evaluated in the present work. Three different polar solvents (acetic acid, a mixture of acetic acid with methanol, and a mixture of acetic acid, methanol, and water) and three different extraction approaches (mechanical shaking, ultrasonic, and microwave-assisted extraction) were used for the extraction of butyltin compounds from PACS-2 certified marine sediment reference material. Before determination by GC--MS, extracted butyltin species were derivatized with sodium tetraethyl borate and extracted into iso-octane. The results indicated that 30-min ultrasonic extraction with 100% acetic acid provided satisfactory recoveries for all certified butyltins. The developed analytical method was successfully applied for determination of butyltin compounds in coastal sediments of the Northern Adriatic Sea. The results demonstrated that butyltins were present in all sediments analysed.

Butyltin Compounds in Sediments of the Bahía Blanca Estuary, Argentina

Systematic measurements of both Tributyltin (TBT) and Dibutyltin (DBT) in sediments along different locations in the inner zone of Bahía Blanca estuary were done. Two samples were taken near the main dry dock facility, at Puerto Belgrano naval base, in Argentina. TBT concentrations from non-detected to 170.3 ng Sn g(-1) were measured in the inner region of the estuary, and higher one of 3,288 ng Sn g(-1) near the dry dock at Puerto Belgrano. DBT values ranging between non-detected and 75.2 ng Sn g(-1) were obtained along the principal channel, but extreme concentration of 1,645 ng Sn g(-1) was measured at Puerto Belgrano. These values show that this estuary is affected by organotin pollution, mainly in areas of heavy shipyard activities.

Single and multiple spike procedures for the determination of butyltin compounds in sediments using isotope dilution GC-ICP-MS

The combined use of single and multiple spike solutions for the determination of butyltin compounds in sediments by species-specific isotope dilution mass spectrometry has been evaluated in this work in order to validate an analytical procedure proposed for routine determinations. For this purpose, a test sediment sample was analysed during the course of an intercomparison exercise using both a single isotope spike solution (a mixture of mono-, di- and tributyltin enriched in 119Sn) and a triple spike solution containing each butyltin species enriched with a different tin isotope. The triple spike methodology (able to correct for interconversion reactions) was employed for the optimisation of the microwave assisted extraction procedure that was subsequently applied for the analysis of the test sediment. The determination of butyltin compounds in the test sediment was performed using both spike solutions under the same extraction conditions. An excellent agreement between the results obtained using both approaches and those provided by all laboratories participating in the intercomparison exercise was obtained, validating in this way the methodologies employed in this work. Uncertainty budgets were calculated for both spiking methodologies. The complexity of the triple spike methodology, in which the simultaneous measurement of nine tin isotope ratios must be carried out, provided additional sources of error in obtaining degradation-corrected concentrations of the three butyltin species. Additionally, uncertainty budgets were obtained also for the calculation of degradation factors F1 (degradation of TBT to DBT) and F2 (degradation of DBT to MBT). The results demonstrated that their uncertainty was independent of the uncertainty of the measurement of the concentration of the butyltin species, both in the spike solution and in the sample, when using a multiple spiking approach, and depended only on the measured isotope ratios and on the uncertainty in the isotopic composition of the spike.

Application of a Gas Chromatography/Mass Spectrometric Method for the Determination of Butyltin Compounds in Sediment

A gas chromatography/mass spectrometric (GC/MS) method has been developed for the determination of trace mono-n-butyltin (MBT), di-n-butyltin (DBT), and tri-n-butyltin (TBT) compounds in sediments. Samples were extracted by 10% acetic acid in methanol containing 0.03% tropolone and were then derivatized for GC/MS analysis. Ethylation by sodium tetraethylborate and phenylation by sodium tetraphenylborate were evaluated as a derivatization reaction of the organotins in sample extract. n-Hexane was added into reaction media in the beginning of the reaction for the continuous extraction of derivatized organotins. Ethylation requires less than 2 hours to get proper derivatization yields for MBT, DBT, and TBT altogether and produces relatively low amounts of side reaction products. Compared to ethylation, phenylation requires much longer time but provides relatively lower yield and produces considerable amounts of side reaction products. Therefore, the ethylation reaction was applied for the analysis of organotin compounds in sediment. An isotope dilution mass spectrometric (IDMS) method based on GC/MS has been applied to the accurate determination of DBT compounds in the sediments. The IDMS results from the analyses of sediment samples showed a reasonable repeatability and a good agreement with the values obtained by IDMS based on liquid chromatography/induced coupled plasma/mass spectrometry.

Speciation analysis of butyltin compounds in sediments of the Theoule harbour (France) by GC/AES

Over the last years, great progress in the research on speciation of butyltins has been made. Many coupling techniques have been successfully developed, with better applications to sediments samples in the environment. Sediments were collected from 1999 to 2000 to elucidate butyltin pollution in Theoule harbour. Most of the analysed samples showed evidence of butyltin compounds. The results show that the concentration of Tributyltin (TBT) was in the range 20–200 µg/kg in March 1999, 20–340 µg/kg in June 1999, 180–1280 µg/kg in July 2000, and 55–820 µg/kg in October 2000. A comparison of the MBT, DBT, and TBT results show that in 1999 the concentrations were in the order TBT<DBT<MBT while in 2000 these concentrations were in the order TBT > DBT > MBT, with some exceptions. The patterns observed in many sediment cores show a great disparity of organotin input concentration among the cores collected during one month and also during two different months, and from one season to the other. This paper provides information on the use of the acetic acid leaching system in the determination of butyltin. The method is applied to evaluate the occurrence of these species in sediments from the Theoule harbour, between 1999 and 2000. In this study, a GC/AES was applied, complemented with acetic acid leaching and monitored using two certified reference materials: PACS-2 reference sediment and BCR 462 (Report EUR 18406 EN, 1998).

SPME-GCMS for speciation of butyltin compounds in marine environment

A method for determination of butyltin species using SPME-GCMS in environmental samples has been standardised. The ionic butyltin compounds present in seawater and sediment samples were converted to their hydride forms using sodium tetrahydroborate (NaBH 4 ). These derivatized compounds were extracted using headspace solid phase microextraction (SPME) technique. A polydimethylsiloxane (PDMS) coated fibre (100 μm film thickness) was used to extract butyltin hydrides. The extracted analytes were then transferred to a GC-MS system for desorption, separation and quantification. The detection limits obtained with SPME-GCMS for monobutyl, dibutyl and tributyl tin compounds for different matrices varied between 0.1 and 0.5 picogram. The optimized method was applied for the speciation study of butyltin compounds in seawater and sediment from different part of the Thane Creek. The levels of butyl tin compounds in sediments of Thane Creek varied from 32-178 ng/g while in Creek water it varied from 2-35 ng/l.

Butyltin compounds in sediment and molluscs from the shipping strait between Denmark and Sweden

The distribution of tributyltin (TBT) contamination in the subtidal zone of the waters between Denmark and Sweden was investigated in relation to major international shipping lanes. Sediment and different benthic molluscs were sampled in transects along and perpendicularly to the shipping lanes in the Sound (Øresund) and the Kattegat/Skagerrak region. The samples were analysed for TBT and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), using GC-PFPD. In sediments, the TBT concentration ranged from <1 to 19 ng g −1 dry weight (dw) with a strong correlation between the TBT concentration and the organic fraction in sediment ( r 2=0.90) in the samples collected in the Sound, where the highest concentrations were found. This relationship was not observed in the samples from the Kattegat because the TBT concentration in most sediment samples was below the limit of detection. In the molluscs, TBT and its degradation products were detected in all samples from the entire area with concentrations ranging from 8.1 ng g −1 dw in Buccinum undatum to 1316 ng g −1 dw in Nuculana pernula. The deposit-feeding bivalve N. pernula was found to have a particularly high accumulation potential for TBT. In addition, a strong correlation between TBT concentrations in sediment and N. pernula was found. Therefore this species seems to be an ideal organism for monitoring sediment contamination. The TBT concentration in N. pernula was found to decrease gradually along the shipping lanes from the Sound, through the Kattegat and into the Skagerrak.

Horizontal and vertical distribution of butyltin compounds in sediments from shipyards in Korea.

Butyltin compounds were quantitatively determined in surface sediment and sediment core samples near shipyards in the south coast of Korea, which is one of the major ship building industries in the world. Tributyltin (TBT) concentrations reached up to 46100 ng Sn/g on a dry-weight basis at the front of the shipyard. Horizontal distribution of butyltin compounds was closely related to dry-docking activities. Butyltin concentrations were relatively low where remote from the sources. The vertical distribution of TBT in sediment cores showed active use of TBT in Korean peninsula for the past decades. The increase of TBT concentrations in sediment core according to estimated sediment age demonstrated a positive correlation with the increase of gross tonnage of ships built in the shipyard for 20 years. High TBT residue levels in sediment core samples raise concerns over persistence of the compound in the marine environment.

Butyltin compounds in sediments from the commercial harbor of Alexandria City, Egypt

AbstractTributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) compounds were quantitatively determined in surface‐sediment samples collected from 23 sites in the commercial harbor of Alexandria City, Egypt. Butyltin concentrations in sediments varied widely depending on the sample location, ranging from less than 0.1 to 186 ng g−1 of Sn for MBT, less than 0.1 to 379 ng g−1 of Sn for DBT, and 1 to 2,067 ng g−1 of Sn for TBT. Elevated TBT concentrations, ranging from 727 to 2,067 ng g−1 of Sn were observed in harbors, marinas, and near ship‐repair facilities, indicating that the butyltin‐containing, antifouling paints of boats and vessels are the major source of butyltin contamination. The TBT concentration decreased rapidly away from potential source areas of boat docking and repair facilities. The high relative concentrations of TBT in the sediments indicated that degradation processes in the sediments are minor, probably due to the anoxic sedimentary conditions at the sampling sites and/or relatively fresh input of TBT to these sites.

Evaluation of extraction techniques for the determination of butyltin compounds in sediments using isotope dilution-GC/ICPMS with 118Sn and 119Sn-enriched species.

Different liquid-solid extraction techniques, including room-temperature leaching with mechanical shaking, ultrasonic, and microwave-assisted extractions, have been evaluated for the quantitative speciation of tin for mono-, di-, and tributyltin (MBT, DBT, and TBT, respectively) in PACS-2 and BCR-646 certified reference materials. A methanol-acetic acid mixture was used as the extractant reagent in all cases. For this purpose, a mixed spike containing 119Sn-enriched MBT (79.7 At%), 118Sn-enriched DBT (86.7 At%), and 119Sn-enriched TBT (83.1 At%), was synthesized, characterized, and used for isotope dilution analysis. The isotopic composition of the mixed spike was determined by gas chromatography/ICPMS after aqueous ethylation using sodium tetraethylborate, and the determination of the concentration of the different species in the spike was performed by means of reverse isotope-dilution analysis using natural MBT, DBT, and TBT standards. In the analysis of the certified sediments, the sample was spiked with the mixed spike, extracted under different conditions, derivatized with sodium tetraethylborate, and extracted into hexane, and the isotope ratios 120/118 and 120/119 were measured as peak area ratios for all butyltin species after GC/ICPMS. Mass bias was corrected using a derivatized natural standard every three sample injections. Sequential degradation reactions during extraction (from TBT to DBT, from DBT to MBT, and from MBT to inorganic tin) were assumed, and mathematical equations were developed that allowed the determination of the correct species concentration and the decomposition factor for each of the transformation reactions. For ultrasonic extraction and mechanical shaking, negligible degradation reactions were observed. However, for microwave assisted extractions, degradation factors up to 7% (TBT to DBT) and 16% (DBT to MBT) were obtained for both reference materials when high-MW energy was applied in the extraction step. For the three extraction techniques tested, the DBT and TBT concentration values obtained for PACS-2 closely matched the certified values. However, for MBT the concentrations found by microwave and ultrasonic extraction were much higher than the certified value. This was not the case for mechanical shaking. The results obtained for BCR-646 using microwave assisted extraction were in good agreement with the certified values for all tin species.

Simultaneous determination of butyltin and phenyltin species in sediments using ultrasound-assisted leaching.

A fast and simple procedure is presented for the simultaneous leaching of butyl (mono, di and tributyl) and phenyl organotin species from sediment samples. Leached compounds are further ethylated with sodium tetraethylborate in aqueous medium, and analyzed by gas chromatography. After testing the stability of triphenyltin under different extraction conditions, ultrasound-assisted leaching at room temperature in the presence of acetic acid was been proposed as an extraction procedure compatible with the simultaneous determination of phenyl- and butyltin compounds in sediments. Recoveries between 70 and 90% were obtained for phenyl species in spiked samples prepared in the laboratory. Results for butyltin species were validated by use of the reference material PACS-2. Quantification limits, using GC-MIP-AES as measurement technique, were approximately 5-10 ng g(-1). Precision in the consecutive analysis of three sediment samples varied between 3 and 10%.

Headspace solid-phase microextraction of butyltin species in sediments and their gas chromatographic determination

A rapid and solvent-free procedure for the simultaneous determination of mono-, di-, and tributyltin in sediments by headspace solid-phase microextraction (SPME) is described. The butyltin chlorides present in sediments were converted into their hydride forms by potassium tetrahydroborate prior to extraction. A quartz fiber coated with 100 μm film of polydimethylsiloxane (PDMS) is introduced into the headspace over the matrix to extract butyltin hydrides. After extraction, the fiber is directly inserted into the injector of the gas chromatograph (GC) for desorption, separation, and quantification. A laboratory modified flame photometric detector using quartz surface-induced tin emission (QSIL-FPD) was used throughout the experiment. The detection limits obtained with SPME-GC-QSIL-FPD for mono-, di-, and tributyltin are 8.8, 0.16, and 0.05 ng/g as Sn, respectively. The proposed method has been validated by analyzing standard reference material CRM-462, and successfully used for the determination of butyltin compounds in sediment collected from coastal areas of Hong Kong.

Determination of (mono-, di- and) tributyltin in sediments. Analytical methods

Methods for the reliable determination of butyltin compounds in sediments are required for both national and international marine monitoring programmes. This evaluation of current commonly used approaches to the analysis identifies critical aspects of extraction, derivatisation, clean-up, separation, standardisation and detection with the objective of improving the analytical capabilities both of experienced laboratories and of those addressing the problems for the first time.

Butyltin compounds in sediment and fish from the Polish Coast of the Baltic Sea.

Concentrations of mono- (MBT), di- (DBT), and tri-(TBT) butyltin compounds were measured in eggs, liver, and muscle of nine species of fish from four regions of the Baltic Sea - the Firth of Vistula, the Gulf of Gdańsk, Puck Bay, and the mouth of the Vistula River. The overall concentration ranges among all the fish sampled from the four sites were: < 7 to 79 ng/g for MBT, 6 to 1100 ng/g for DBT, 7 to 3600 ng/g for TBT, and 16 to 4800 ng/g for total BTs, on a wet wt basis. The highest concentration of total BTs was found in herring liver from the Firth of Vistula (4800 ng/g, wet wt) and in roach muscle from Puck Bay (3300 ng/g, wet wt), while the least concentration was found in burbot eggs and liver from the Vistula River (39 and 32 ng/g, wet wt, respectively). TBT was the major form of BTs present in most samples analyzed. Sediment samples collected from shipyards in the Gulf of Gdańsk contained butyltin concentrations ranging from 1.2 to 46 microg/g (dry wt) for MBT, 2.0 to 42 microg/g for DBT, and 2.6 to 40 microg/g for TBT. As with the fish, the majority of the BTs in sediment were present as TBT, which suggested recent exposure of the aquatic environment of the region to TBT.

Effects of complexing agents and acid modifiers on the supercritical fluid extraction of native phenyl- and butyl-tins from sediment

The effects of: (1) the modifier type (methanol and formic, acetic and propionic acids), (2) complexing agents (diethylammonium diethyldithiocarbamate, ammonium pyrrolidinedithiocarbamate) either with or without acidic modifiers, (3) the extraction temperature (50–80 °C) and pressure (30–50 MPa), (4) the extraction procedure (static–dynamic or dynamic), and (5) the volume of static modifier, on the extraction efficiency of native butyl- and phenyl-tin compounds from sediment, were evaluated comprehensively. The highest extraction efficiency for butyl- and phenyl-tin compounds was obtained at 30 MPa and 50 °C by using CO2 modified with acetic acid (200 μl in the cell). Supercritical fluid extraction (SFE) extracts were hexylated and determined by GC–FPD using a 610 nm bandpass filter without any clean-up step. In summary, the developed analytical procedure is robust (no restrictor clogging; free from FPD interferences), it is low-cost (no complexing agents needed), it has a high sample throughput (<3 h), it is independent of the matrix for the determination of butyltin compounds in sediment, and it provides the highest precision among the SFE procedures reported for organotin determination. © 1998 John Wiley & Sons, Ltd.

Contamination by butyltin compounds in sediments from Thailand

Butyltin compounds (BTs) including tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) were analysed in sediments collected from coastal areas of Thailand in 1995. Contamination by BTs have been widespread along the coastal areas with concentrations of MBT, DBT and TBT in surface sediments ranging from 7 to 410, 2 to 1900 and 4 to 4500 ng g −1 (dry weight basis), respectively. High TBT concentrations were associated with large commercial or far seas vessels areas, while the levels at high fishing boat and coastal mariculture areas were lower. Large commercial ship and fishing boat hulls might be significant sources of BT contamination in Thailand coastal waters. Degradation of TBT in sediments might be higher in tropics than in sub-tropical zone. To our knowledge, this is a first report on the detection of BTs in sediments from Thailand.

Determination of Butyltin Compounds in Sediments by Means of Hydride Generation/Cold Trapping Gas Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometric Detection

A procedure for the determination of butyltin compounds in sediments is described. The method is based on the generation of volatile mono-, di- and tributyltin (MBT, DBT, TBT) hydrides from a 4% (v/v) acetic acid medium using NaBH4. The hydrides formed are then trapped on a Chromosorb W HP SP2100 packed glass column immersed in liquid nitrogen. Sequential desorption of the hydrides is achieved by Nichrome wire heating of the column. The MBT, DBT and TBT hydrides are detected by mass spectrometry using an inductively coupled plasma source. Detection limits of 7, 4 and 4 pg (as Sn) for MBT, DBT and TBT, respectively, were obtained. The method was applied to the determination of organotin compounds (DBT and TBT) in the certified reference material CRM 462 with satisfactory results. © 1997 by John Wiley & Sons, Ltd.

Determination of Butyltin Compounds in Sediments by Means of Hydride Generation/Cold Trapping Gas Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometric Detection

Determination of Butyltin Compounds in Sediments by Means of Hydride Generation/Cold Trapping Gas Chromatography Coupled to Inductively Coupled Plasma Mass Spectrometric Detection