Acid extraction treatment of sediment samples for organotin speciation; occurrence of butyltin and phenyltin compounds on the cadiz coast,south-west spain

A method is described for leaching of nanogram amounts of mono-, di and tri-butyltin compounds and mono-, di- and tri-phenyltin compounds from sediments. The procedure is based on soaking the sediments in a water–hydrogen bromide mixture (2:3) with magnetic stirring for 1 h followed by extraction with 0.02% (w/v) tropolone solution in pentane for 2 h. Organotins are determined by GF FPD after clean-up through a Florisil column and derivatization by Grignard pentylation. The method has been applied to the study of water and sediments in different areas of south-west Spain. Predominant species are butyltins, especially tributyltin (TBT), which has high values in waters and sediments of Puerto de Santa Maria and Cadiz Bay, as well as in sediments of the Sancti Petri Channel, which suggests a harmful action on biota. A direct relation has been found beween organotin levels and distance of potential focus determined by boating activities. In addition, the relative occurrence of dibutyltin (DBT) and monobutyltin (MBT) together with TBT has been noted, possibly as a result of a degractation process, and the influence of grain size of sediment and presence of organic matter on organotin accumulation has been studied.     

Analytical methods and problems related to the determination of organotin compounds in marine sediments

The determination of organotin compounds in bottom sediments is a complex process that requires a number of analytical steps, i.e. sample collection, transport and storage; extraction of analytes from sediment; derivatization; extract purification; enrichment; and the final chromatographic measurement. The whole process is time and labour consuming, and subject to securing sample representativeness. In this review the most frequently encountered problems and the examples of possible analytical solutions are presented, which encompass the specific steps of speciation analysis of these toxic compounds.     

Contamination and biomethylation of organotin compounds in pearl/fish culture areas in Japan.

Uwakai of Japan is famous for pearl and yellowtail fish culture. Recently, pearl culture farming in that region has suffered from a low production of pearls. An illegal use of organotin antifouling paints on fishing nets was reported. In the line of pollution studies, thus, the present investigation was carried out to examine the contamination status and fate of organotin compounds. Totally, 23 water, 10 sediment and 8 pearl oyster tissue samples were analyzed for tributyltin (TBT), triphenyltin (TPT), and their breakdown products (di- and mono compounds) by gas chromatography combined with inductively coupled plasma mass spectrometry (GC/ICP-MS). The results show that the TBT concentrations in water, sediment and biota were in the range from 0.11 to 10.6 ng Sn l(-1), 0.35 to 2500 ng Sn g(-1), and 50.4 to 181 ng Sn g(-1), respectively. The values for sediment and biota are expressed on the dry-weight basis. Triphenyltin in water, sediment and biota were in the range from 0.009 to 0.108 ng l(-1), non-detect to 12.7 ng g(-1), and non-detect to 6.83 ng g(-1), respectively. Although the TBT concentration in seawater is below the tentative assessment level of 10 ng l(-1) set by the Japanese Environment Agency in 1992, it may cause endocrine disruption/other effects in aquatic organisms. Octyltin compounds (mono-, di- and trioctyltin) were also quantified in seawater and sediment. The detection of dibutyldimethyltin (DBDMT) and tributylmonomethyltin (TBMMT) in sediment (methylated butyltins comprised 2.8-31% of total butyltins), and TBMMT in seawater suggested that biomethylation of anthropogenic tributyltins is a significant transformation pathway in the coastal environment.     

Speciation of organotin compounds in marine sediments by capillary column gas chromatography-atomic absorption spectrometry coupled with hydride generation

A method for speciation of organotin compounds in marine sediments by solvent extraction combined with hydride generation gas chromatography-atomic absorption spectrometry has been developed. Sediment samples spiked with tributyltin and triphenyltin chlorides were homogenized in hydrochloric acid. The chlorides were extracted twice into toluene. Recoveries of the organotin compounds from the spiked sediment samples were improved by the addition of 8-quinolinol. Tributyltin and triphenyltin chlorides form ion-associates with 8-quinolinol in aqueous hydrochloric acid. The method was optimized with respect to derivatization reactions and extraction conditions. Interferences from Sn(II/IV) and additional 13 ions were investigated. Recoveries of 84-100% for tributyltin and 86-100% for triphenyltin were achieved using this method. The detection limits obtained for tributyltin and triphenyltin chlorides were 95 and 145 pg, respectively, corresponding to a relative detection limit of 95 and 145 ng kg(-1) in the sediment.     

Determination of organotin compounds in marine sediments using graphite furnace atomic absorption spectrometry

Organotin compounds, especially tributyltin, began to cause concern 10 years ago due to a high toxicity towards marine organisms. Several methods of analysing organotin compounds in various matrices have already been developed to determine organotin species simultaneously, but these are quite expensive as special equipment and specialized staff are needed. A simple screening method, which determines the organic tin compounds in the sediment, has therefore been developed and validated. The method can easily be implemented in laboratories accustomed to tracelement analyses; the sediment is extracted by a two-phase extraction and the organic extract is analysed using graphite furnace atomic absorption spectrometry (GF AA.) The screening method has been validated using high-pressure liquid chromatography-inductively coupled plasma mass spectrometry (HPLC–ICP MS).     

Tartaric acid extraction of organotin compounds from sediment samples

A new extraction method for the determination of tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT) in sediments based on extraction with tartaric acid and methanol has been developed. Tin species were extracted from sediment samples using focused microwave technology, then ethylated with sodium tetraethylborate (NaBEt₄) and analyzed by isotope dilution (ID) gas chromatography-mass spectrometry (GC-MS). The advantages of such methodology in comparison with other established extraction methods for the routine speciation analysis of organotin compounds are discussed with respect to sulfur interferences co-extracted from complex matrices.Interferences from elemental sulfur are normally found with acetic acid extraction, but with tartaric acid extraction these interferences were eliminated, demonstrating selective extraction.The accuracy of the analytical procedure was established by analyzing a certified reference material (CRM) (PACS-2, marine sediment) and comparing the results to the certified values. Good agreement between determined and certified values for butyltin compounds was obtained. Finally, some complex sediment samples collected from San Vicente's Bay, Chile, were analyzed with the proposed methodology, demonstrating its potential value for monitoring butyltins in environmental samples with high concentrations of sulfur compounds.     

Determination of fifteen priority phenolic compounds in environmental samples from Andalusia (Spain) by liquid chromatography–mass spectrometry

This work describes the optimisation of a method to determinate fifteen phenolic compounds in waters, sediments and biota (green marine algae) by liquid chromatography coupled to mass spectrometry (LC-MS) with atmospheric pressure chemical ionisation (APCI) in the negative mode. The LC separations of the studied compounds and their MS parameters were optimised in order to improve selectivity and sensitivity. Separation was carried out with a C₁₈ column using methanol and 0.005% acid acetic as mobile phase in gradient mode. The molecular ion was selected for the quantitation in selective ion monitoring (SIM) mode. A solid-phase extraction (SPE) method was applied in order to preconcentrate the target analytes from water samples. However, extraction of the compounds from sediment and biota samples was carried out by liquid–solid extraction with methanol/water after studying the influence of other organic solvents. In addition, a clean-up step by SPE with HLB Oasis cartridges was necessary for sediments and biota. The proposed analytical methodology was validated in the target environmental matrices by the analysis of spiked blank matrix samples. Detection limits were 10–50 ng L^–1 for water, 1–5 g kg^–1 for sediments and 2.5–5 g kg^–1 for biota samples. Good recoveries and precision values were obtained for all matrices. This methodology has been successfully applied to the analysis of incurred water, sediment and biota samples from Andalusia (Spain).     

Speciation of butyltin compounds in marine sediments by preconcentration on C60 and gas chromatography-mass spectrometry

A new method for the speciation of butyltin compounds by solid phase extraction and direct injection using gas chromatography-mass spectrometry (GC/MS) is described. The compounds were complexed with sodium diethyldithiocarbamate and retained on a C60 sorbent column. The neutral chelates of butyltin compounds were eluted with ethyl acetate containing NaBPr4 as derivatising reagent. The main analytical figures of merit of the proposed method for 10 ml of sample are: linear range 0.2-35 ng/g expressed as Sn; limits of detection, 0.07, 0.09 and 0.10 ng/g as Sn for monobutyltin, dibutyltin and tributyltin, respectively. No interferences from metal ions such as Zn2+, Fe3+, Sb3t, Pb2+, Ni2+ and Mn2+ were observed in the determination of organotin compounds. The validation of method was performed out by the analysis of a standard reference sediment (CRM 462). The method was also applied to the determination of butyltin compounds in marine sediment samples.     

Supercritical fluid extraction of polyhalogenated pollutants from aquaculture and marine environmental samples: a review

This article focuses on the state-of-the-art in sample preparation using supercritical fluid extraction (SFE), to monitor the content of polyhalogenated pollutants in aquaculture and marine environmental samples. Marine sediments and biological applications, including several types of samples matrices (fish, shellfish, seaweed and fish feed) and analyte groups (polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxin (PCDD)/Fs and organochlorinated pesticide (OCPs)) are discussed with respect to SFE use and optimisation of conditions. We also discuss the great analytical potential of SFE, the integration of the extraction and clean-up steps for rapid sample processing justifying its use for routine work. The most recent SFE applications to the determination of these pollutants in marine environmental (biota and sediment) samples, published in the last 15 years, are reviewed.     

Simple and effective gas chromatographic mass spectrometric procedure for the speciation analysis of organotin compounds in specimens of marine mussels. An evaluation of the organotin pollution of the lagoon of venice

This paper describes a simple, effective analytical procedure, based on a gas chromatographic mass spectrometric technique, for the speciation analysis of organotin compounds (OTC) in mussel samples. The direct alkylation reaction of the organotin chlorides in the aqueous digestion solution by NaBEt(4) allowed a short analysis time and a good recovery. The evaluation of the yield of each step constituting the analytical procedure indicated that the alkylation step is the most critical one. The proposed method was advantageously utilised to monitor the level of OTC pollution of the Lagoon of Venice. All the sites examined, both near to and far from anthropogenic activities, revealed significant levels of OTC pollution.     

Comparison of solid phase extraction, saponification and gel permeation chromatography for the clean-up of microwave-assisted biological extracts in the analysis of polycyclic aromatic hydrocarbons

The feasibility of different clean-up procedures was studied for the determination of polycyclic aromatic hydrocarbons (PAHs) in biota samples such as oysters, mussels and fish liver. In this sense, once the samples were extracted--essentially with acetone and in a microwave system--and before they could be analysed by gas chromatography-mass spectrometry (GC-MS), three different approaches were studied for the clean-up step: solid phase extraction (SPE), microwave-assisted saponification (MAS) and gel permeation chromatography (GPC). The main aim of this work was to maximise the recoveries of PAHs and to minimise the presence of interfering compounds in the last extract. In the case of SPE, Florisil cartridges of 1, 2 and 5 g, and silica cartridges of 5 g were studied. In that case, and with oysters and mussels, microwave-assisted extraction and 5 g Florisil cartridges provided good results. In addition, the concentrations obtained for Standard Reference Material (SRM) NIST 2977 (mussel tissue) were in good agreement with the certified values. In the case of microwave-assisted saponification, the extracts were not as clean as those obtained with 5 g Florisil and this fact lead to overestimate the concentration of the heaviest PAHs. Finally, the cleanest extracts were obtained by GPC. The method was successfully applied to mussels, oysters and hake liver, and the results obtained for NIST 2977 (mussel tissue) were within the confidence interval of the certified reference material for most of the certified analytes.     

A new application of imprinted polymers: Speciation of organotin compounds

Molecular imprinting technology has been employed for the first time to prepare a specifically affinity chromatographic stationary phase for speciation purposes. Tributyltin has been chosen as the template molecule and the non-covalent approach has been applied. Three different polymerization methods have been evaluated: (i) a composite material, (ii) a polymer prepared via-Iniferter grafting; (iii) an emulsion polymer. Columns packed with different polymers have been evaluated by liquid chromatography (LC) coupled to inductively coupled plasma mass spectrometry (ICP-MS). The chromatographic conditions as well as the analytical characteristics of the developed method are discussed in this paper. Our findings have shown formation of specific cavities in the grafted Iniferter as well as in the emulsion polymers with the latter achieving resolution of four organotin compounds. Detection limits are similar to those obtained with commercial, but not specific, stationary phases (6 pg for monobutyltin, MBT; 10 pg for both tributyltin, TBT, and triphenyltin, TPhT; and 20 pg for dibutyltin, DBT). The main advantage of this proposed stationary phase is that good recovery is obtained for all species, including MBT. Baseline resolution for TBT and TPhT has also been obtained. The high selectivity of this column prevents matrix interferences. The method has been validated by analyzing two biota reference materials (ERM-CE477 mussel tissue and T-38 oyster tissue).     

Occurrence and chemical speciation analysis of organotin compounds in the environment: A review

Environmental concerns regarding organotin compounds have increased remarkably in the past 20 years, due in large part to the use of these compounds as active components in antifouling paints [mainly tributyltin (TBT)] and pesticide formulations [mainly triphenyltin (TPhT)]. Their direct introduction into the environment, their bio-accumulation and the high toxicity of these compounds towards “non-target” organisms (for example: oysters and mussels) causes environmental and economic damage around the world. As a consequence, the presence and absence of organotin compounds is currently monitored in a range of environmental matrices (e.g., water, sediment and shellfish) to examine the utility of controls meant to regulate the level of contamination as required in some EC Directives and the Water Framework Directive 2000/60/EC. To evaluate the environmental distribution and fate of these compounds and to determine the effectives of legal provisions adopted by a number of countries, a variety of analytical methods have been developed for organotin determination in the environment. Most of these methods include different steps such as extraction, derivatisation and clean up. The aim of the present review is to evaluate the environmental distribution, fate and chemical speciation of organotin compounds in the environment.     

Speciation of organotin in environmental sediment samples

An optimized sample preparation procedure for organotin speciation in sediment samples has been applied to the analysis of sediments collected in the environment. The method is based on tropolone complexation of the ionic organotins, followed by extraction into a hexane-ethylacetate mixture and derivatization by NaBEt(4). The method was applied to the determination of organotin in various harbour, shipyard and dry-dock sediments in Belgium. Butyltin compounds were detected in all samples analyzed, often at high mg kg(-1) levels. A limited number of samples showed the presence of phenyltin compounds. Further, the method was adapted to the analysis of river sediments sampled from the vicinity of shipyards. Butyltin concentrations were detected at the microg kg(-1) level in the majority of samples.     

Speciation of butyltin compounds in marine sediments with headspace solid phase microextraction and gas chromatography – mass spectrometry

A method for the determination of organotin compounds (monobutyl = MBT, dibutyl = DBT, and tributyltin = TBT) in marine sediments by headspace Solid Phase Microextraction (SPME) has been developed. The analytical procedure involved 1) extraction of TBT, DBT and MBT from sediments with HCl and methanol mixture, 2) in situ derivatization with sodium tetraethylborate and 3) headspace SPME extraction using a fiber coated with poly(dimethylsiloxane). The derivatized organotin compounds were desorbed into the splitless injector and simultaneously analyzed by gas chromatography – mass spectrometry. The analytical method was optimized with respect to derivatization reaction and extraction conditions. The detection limits obtained for MBT, DBT and TBT ranged from 730 to 969 pg/g as Sn dry weight. Linear calibration curves were obtained for all analytes in the range of 30–1000 ng/L as Sn. Analysis of a standard reference sediment (CRM 462) demonstrates the suitability of this method for the determination of butyltin compounds in marine sediments. The application to the determination of TBT, DBT and MBT in a coastal marine sediment is shown.     

The ionic liquid 1-hexadecyl-3-methylimidazolium bromide as novel extracting system for polycyclic aromatic hydrocarbons contained in sediments using focused microwave-assisted extraction

A method to extract PAHs from sediments is carried out using aqueous solutions containing aggregates of the ionic liquid (IL) 1-hexadecyl-3-methylimidazolium bromide (HDMIm-Br) as the extracting medium. Focused microwave-assisted extraction has been used to accelerate the extraction step, followed by HPLC with fluorescence detection without clean-up steps to remove the IL prior to injection. The method has been applied to certified reference sediment BCR-535 and marine sediments from Tenerife (Canary Islands) with successful results. The optimized method gave average absolute recoveries of 91.1% for six of the seven PAHs studied, with relative standard deviations lower than 10.4%. The overall method is characterized for presenting low extraction times (6min), low amounts of the sediment (0.1g), low amounts of IL (45mM), and low volumes of aqueous extractant solution (9mL). The use of small amounts of both IL and aqueous extractant solution allows the method to be considered environmental-friendly.     

Atomic absorption spectrometric screening and gas chromatographic-mass spectrometric determination of organotin compounds in marine mussels: an application in samples from the Venetian Lagoon

A new analytical approach for the determination of organotin compounds (OTC) in mussel samples has been developed and evaluated. A preliminary step, performed by graphite furnace atomic absorption spectrometry (GFAAS) for the total tin determination may be followed by gas chromatographic-mass spectrometric (GC/ MS) speciation only for the characterization of those samples exhibiting total tin concentration higher than 30 ng/g wet weight (GFAAS limit of detection). The GFAAS method was optimized using Pd nitrate under reducing conditions as matrix modifier to minimize NaCl interferences. Organotins were derivatized with a Grignard reagent for GC/MS analysis (TBT limit of detection = 80 ng/g). An application of this strategy was performed on mussel samples collected from the Venetian Lagoon.     

Accelerated extraction for determination of polycyclic aromatic hydrocarbons in marine biota

A rapid and simple method is proposed for determination of polycyclic aromatic hydrocarbons (PAH) in complex matrices such as marine biota. The method uses sonication, by means of an ultrasonic probe, as a new tool for assisted extraction, coupled with reversed-phase liquid chromatography (RP-LC) with fluorescence detection (FL) for determination of 16 US EPA priority PAH. Separation and detection of the 16 PAH were complete in 45 min by RP-LC with a C₁₈ column and acetonitrile–water gradient elution. Multivariate optimisation of the variables affecting extraction (ultrasound radiation amplitude, sonication time, and temperature of the water-bath in which the extraction cell was placed) was conducted. The accuracy of the method was determined by analysis of a certified reference material and comparison of the results obtained with those from another method (microwave-assisted extraction and GC–MS). The new technique avoids the main problems encountered in the determination of PAH in complex matrices such as marine biota, and no clean-up step is necessary. The method was applied to determination of PAH in estuarine biota samples from the Urdaibai estuary (Biscay, Spain).     

Speciation of butyltin compounds in marine sediments with headspace solid phase microextraction and gas chromatography mass spectrometry

A method for the determination of organotin compounds (monobutyl = MBT, dibutyl = DBT, and tributyltin = TBT) in marine sediments by headspace Solid Phase Microextraction (SPME) has been developed. The analytical procedure involved 1) extraction of TBT, DBT and MBT from sediments with HCl and methanol mixture, 2) in situ derivatization with sodium tetraethylborate and 3) headspace SPME extraction using a fiber coated with poly(dimethylsiloxane). The derivatized organotin compounds were desorbed into the splitless injector and simultaneously analyzed by gas chromatography - mass spectrometry. The analytical method was optimized with respect to derivatization reaction and extraction conditions. The detection limits obtained for MBT, DBT and TBT ranged from 730 to 969 pg/g as Sn dry weight. Linear calibration curves were obtained for all analytes in the range of 30-1000 ng/L as Sn. Analysis of a standard reference sediment (CRM 462) demonstrates the suitability of this method for the determination of butyltin compounds in marine sediments. The application to the determination of TBT, DBT and MBT in a coastal marine sediment is shown.     

Simplified sample preparation for GC speciation analysis of organotin in marine biomaterials

Two simple sample preparation methods for the speciation analysis of triphenyltin and butyltin compounds in marine biotissues, using tetramethylammonium hydroxide (TMAH) solubilization and enzymic hydrolysis, have been developed and compared with conventional acid digestion. Derivatization was carried out in situ using sodium tetraethylborate (NaBEt₄) without prior separation of the analytes from the tissue matrix. Separation and detection was performed using capillary gas chromatography (GC) coupled to microwave-induced plasma atomic emission spectrometry (MIP AE) allowing detection limits of 2 ng g^?1 (as tin) to be reached. The accuracy of the presented methods was demonstrated by the analysis of a fish reference material (NIES No. 11). the necessity for sample clean-up is discussed and examples of the analysis of mussel tissue are shown.