The unexpected sources of organotin contamination in aquatic toxicological laboratory studies.

Unaccounted sources of contamination can be problematic in toxicological studies and can range from the presence of impurities, breakdown products or isoforms of the parent compound to the unexpected compounds leaching from dosing apparatus. As these compounds are not being tested, they may not be measured in the dosed aquaria and hence go undetected, potentially contributing as confounding factors in toxicological assessments. In this paper we report the unexpected detection of butyltin compounds (mono, di and tributyltin) in flow-through aquaria waters of an aquatic toxicological set-up. High and variable leaching rates for dibutyltin of 2.0 and 6.6 microg/h were detected during the first week of each of two separate flow-through studies. Following this initial 'surge' of dibutyltin leachate, a decrease in leachate rate was seen with values of 0.9 and 1.2 microg/h by Day 14 (second week of study). The main source of the butyltin leachates was shown, to be the airline tubing used in the assembly of the air-supply into each flow-through tank. A 24h period of incubation of the airline tubing with clean water led to the leaching of concentrations of 63.8 ng/l TBT-Sn, 1638.8 ng/l DBT-Sn and 4054.6 ng/l MBT-Sn. The concentration of tributyltin detected was within its toxicologically effective range and as such could have potentially confounding effects on the toxicological bioassays being used. These accidental findings could be of enormous relevance to aquatic toxicologists and have an important bearing on the choice of materials used to construct experimental exposure aquaria.

A multispecies approach for monitoring persistent toxic substances in the Gulf of Gdansk (Baltic sea).

Bivalve mussels are usually used for biomonitoring persistent toxic substances (PTS) in coastal ecosystems. Nevertheless, these organisms, which live attached on hard substrates, can be found along the sandy coasts only on human manufactured products. In this work different species collected in the Gulf of Gdansk were compared to evaluate their suitability for monitoring PTS pollution at a local scale. The clam Mya arenaria seems to represent an excellent indicator of sediment pollution, mainly for organotin compounds which are selectively bioaccumulated. Organochlorine compounds are bioaccumulated in the different species mainly in function of their lipid body burden. Habitat conditions (salinity, substrate, pollution), however, strongly limited the occurrence of different species in the sampling sites; the most ubiquitous species, the common shrimp Crangon crangon, resulted therefore the most suitable to be used for the comparison of PTS pollution in this aquatic environment. Although the blue mussel (Mytilus trossulus) was confirmed to be a very useful sentinel species to compare pollution level inside and outside the Gulf of Gdansk, we recommend the use of other species to give a more detailed picture of the pollution situation in coastal areas.

Some chemical contaminant of surface sediments at the Baltic Sea coastal region with special emphasis on androgenic and anti-androgenic compounds.

Androgenic and anti-androgenic compounds including p,p'-DDE, Diuron, Linuron, Fenarimol, Vinclozolin, 1-(3,4-dichlorophenyl) urea (DCPU), 1-(3,4-dichlorophenyl)-3-methylurea, (DCPMU), tributyltin (TBT) and triphenyltin (TPT) and their metabolites (DBT, MBT, DPT, MPT) as well as metallic elements (Ni, Cu, Zn, As, Cd, Pb, Co, Tl, Cr, Fe, Mn, Al, K, Mg, Na, Ca, Ba, Ti, Sn), PAHs (16 indicator compounds), DDTs and PCBs have been quantified in top layer (0-10 cm) of up to 37 surface sediment samples collected from several sites in costal zone of the Gulf of Gdansk, an inland freshwater area of Brdyujscie in Poland and the tidal flats of the Norderney Island, Wadden Sea in 2002-2003. These sites differed in the degree of anthropogenic activities, including chemical pollution and related impact on biota. Especially in sediments near shipyards, ship repair facilities, harbours, other industrial activities or close to municipal sewage treatment plant outlets butyltins, PAHs and some metallic elements were found at high concentrations. Diuron, Linuron and DCPMU were detected at a few sites, Fenarimol only once, while Vinclozolin and DCPU were not detected. DDT concentrations in the sediments from the Gdansk and Gdynia region of the Gulf show a stepwise decrease following the ban for production and use, while diffusion of PCBs at some industrial sites seems to continue. Elevated PAH concentrations in sediments seem to be mainly due to pyrogenic and less to mixed pyrogenic and petrogenic sources, while for a few sites rather petrogenic sources dominated. The reference sites in the Norderney Island, Wadden Sea showed similar or slightly higher loads of DDTs, BTs, PAHs, PCBs and metallic elements when compared to sediments from the least contaminated sites in the coastal Gulf of Gdansk area, while phenyltins were not detected at both spatially distant European areas.

Determination of chloroacetanilides, triazines and phenylureas and some of their metabolites in soils by pressurised liquid extraction, GC-MS/MS, LC-MS and LC-MS/MS.

Pressurised liquid extraction (PLE) technique was used for the simultaneous extraction of phenylureas, triazines and chloroacetanilides and some of their metabolites from soils. Extractions were performed by mixing 15 g of dried soil with 30 mL of acetone under 100 atm at 50 degrees C, during 3 min and with three PLE cycles. Prior to the analysis of naturally contaminated soils, each of the five representative soil matrices used as blanks (of different depths) was spiked in triplicate with standards of each parent and degradation compound at about 10, 30 and 120 microg/kg. For each experiment, isoproturon-D6 and atrazine-D5 were used as surrogates. Analysis of phenylureas and metabolites of triazines and phenylureas was carried out by reversed phase liquid chromatography/mass spectrometry (LC-MS) and LC-MS/MS in the positive mode. Gas chromatography (GC)/ion trap mass spectrometry was used in the MS/MS mode for the parent triazines and chloroacetanilides. The average extraction recoveries were above 85%, except for didesmethyl-isoproturon, and quantification limits were between 0.5 and 5 microg/kg. The optimised multi-residue method was applied to soils and solids below the root zone, sampled from agricultural plots of a small French hydrogeological basin.

Determination of oxanilic and sulfonic acid metabolites of acetochlor in soils by liquid chromatography-electrospray ionisation mass spectrometry.

An analytical method is presented that describes the extraction and quantification of oxanilic and sulfonic acid metabolites of the herbicide acetochlor in soil samples. Experiments were performed on 50 g of soil using a solvent extraction technique with an acetonitrile-water (60:40) mixture in an acidic medium. Analysis was carried out by reversed-phase liquid chromatography and detection by electrospray ionisation mass spectrometry in single ion monitoring and negative modes. Four different soil matrices were spiked in triplicate with standards of each degradation compound at three concentration levels between 2 and 80 microg/kg. The average recoveries range from 90 to 120% for both the metabolites, with relative standard deviations lower than 15%. The limits of quantification are about 1 and 2 microg/kg for the ethanesulfonic acid and the oxanilic acid metabolites, respectively. The method has been applied to soils and solids recovered from the deeper unsaturated zone of a small French catchment closely monitored as part of the European project "Pesticides in European Groundwaters: detailed study of Aquifers and Simulation of possible Evolution scenarios (PEGASE)".

Prediction of the impact of the Aznalcóllar toxic spill on the trace element contamination of agricultural soils.

The interaction of several trace elements (Cd, Zn, Cu, Pb, As, Bi, and Tl) was studied by leaching experiments in agricultural soils affected by the Aznalcóllar toxic spill. The spill led to contamination by acid waste waters and sludge deposition. The levels of contamination recorded after the sludge was removed from soils showed that highly contaminated areas remained. A comparison of soils directly affected by sludge deposition and acid waste waters with soils contaminated only by acid waste waters demonstrated that Zn/As and Cd/As ratios were good indicators of the two contributions to the contamination. Soil samples were characterised and grouped according to their texture and carbonate content. The response of elements to single extractions with CaCl2 0.01 mol l-1, CaCl2 1 mol l-1, CH3COOH 0.43 mol l-1, and EDTA 0.05 mol l-1 enabled us to estimate their mobility in the soils. Cd and Zn were found to be the most mobile elements. Cu showed an intermediate mobility, especially in an acidic medium. Pb, As, Bi and Tl were found to be non-mobile elements. A comparison of referent, low and highly contaminated samples showed that the presence of sludge had an effect on desorption yields, in part due to the short-term after the contamination. Calculations of a relative scale of long-term mobility, between soils and trace elements, provided further conclusions derived from the use of single extractions.

Speciation of arsenic in mussels by the coupled system liquid chromatography-UV irradiation-hydride generation-inductively coupled plasma mass spectrometry.

A method has been developed for the determination of seven arsenic species in mussel tissues by liquid chromatography-hydride generation-UV photo-oxidation and detection by inductively coupled plasma mass spectrometry. In order to determine the different species, two ion-exchange columns (anionic and cationic) were used with phosphate and nitric acid/ammonium nitrate as mobile phases, respectively. The optimisation of the conditions for separation, photo-oxidation and hydride generation is described. For each of these species, the limits of detection and repeatability are reported with the entire system coupling. This system was applied to the analysis of certified reference material (CRM 278) and mussels collected from Barcelona harbour. Extractions were achieved in methanol/water (1:1) using low-power focused microwaves as leaching process. As expected, arsenobetaine was the main compound extracted from both materials; the typical concentrations found were between 1 and 7 mg kg(-1). Other organoarsenical compounds, probably arsenosugars, were extracted in a concentration range of 0.3-1.5 mg kg(-1) in both cases. Amounts of dimethylarsinate (DMA) were found to be significant in the CRM 278, but very low in mussels from Barcelona harbour. The low limits of detection of the coupled system allow us to quantify low contents of other species (As(V), arsenocholine and monomethylarsonate (MMA)).