New sediment reference material for the quality control of butyltin and phenyltin analysis

Endocrine-disrupting chemicals in coastal lagoons of the Po River delta: sediment contamination, bioaccumulation and effects on Manila clams

The large estuary that the River Po forms at its confluence into the Adriatic Sea comprises a multitude of transitional environments, including coastal lagoons. This complex system receives the nutrients transported by the River Po but also its load of chemical contaminants, which may pose a substantial (eco)toxicological risk. Despite the high ecological and economic importance of these vulnerable environments, there is a substantial lack of information on this risk. In light of the recent amendments of the European Water Framework Directive (2013/39/EU), the present study investigated the sediment contamination of six coastal lagoons of the Po delta and its effects on Manila clams (Ruditapes philippinarum), exposed in situ for 3 months. Sediment contamination and clam bioaccumulation of a wide range of chemicals, i.e. trace metals (Cd, Cr, Ni, Hg, Pb, As), polybrominated diphenyl ethers (PBDEs), alkylphenols (APs), organochlorine compounds (PCBs, DDTs), polycyclic aromatic hydrocarbons (PAHs) and organotins (TPhT, TBT), suggested a southward increase related to the riverine transports. Where the River Po influence was more direct, the concentrations of contaminants were higher, with nonylphenol and BDE-209 exceeding sediment quality guidelines. Biometric indicators suggested the influence of contamination on organism health; an inverse relationship between PBDEs in sediments and clam condition index has been found, as well as different biota-sediment accumulation factors (BSAFs) in the lagoons.

Baseline of the butyltin distribution in surface sediments (0-20 cm) of the Elbe estuary (Germany, 2011)

The concentrations of the butyltin (BT) species tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) were measured in the surface sediments (0-20 cm) at 29 sites of the Elbe estuary in 2011. TBT values ranged from 'undetectable' to 41 ng Sn g(-1) dry weight (d.w.) with the two highest values measured in the inner section of the estuary near the port of Hamburg (32 and 41 ng Sn g(-1) d.w.). TBT, DBT, and MBT showed significant decreases towards the estuarine mouth (Spearman's rho -0.660, -0.685, and -0.583, respectively, p<0.001). The degradation of TBT, assessed by the BT degradation index (BDI), showed a rising trend from the port of Hamburg towards the mouth of the estuary, though not a significant one (Spearman's correlation, p=0.066). Annual sedimentation rates did not show any significant correlations (Spearman's correlation) to BT pollution or to the butyltin degradation index (BDI).

Development of candidate reference materials for the measurement of lead in bone

The production of modest quantities of candidate bone lead (Pb) reference materials is described, and an optimized production procedure is presented. The reference materials were developed to enable an assessment of the interlaboratory agreement of laboratories measuring Pb in bone; method validation; and for calibration of solid sampling techniques such as laser ablation ICP-MS. Long bones obtained from Pb-dosed and undosed animals were selected to produce four different pools of a candidate powdered bone reference material. The Pb concentrations of these pools reflect both environmental and occupational exposure levels in humans. The animal bones were harvested post mortem, cleaned, defatted, and broken into pieces using the brittle fracture technique at liquid nitrogen temperature. The bone pieces were then ground in a knife mill to produce fragments of 2-mm size. These were further ground in an ultra-centrifugal mill, resulting in finely powdered bone material that was homogenized and then sampled-scooped into vials. Testing for contamination and homogeneity was performed via instrumental methods of analysis.

Assessment of butyltin and phenyltin pollution in the sea mullet, Mugil cephalus, along the Moroccan and Spanish coasts (Mediterranean Sea)

Levels of three butyltin (BTs) compounds, monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT), and three phenyltin (PTs) compounds, monophenyltin (MPhT), diphenyltin (DPhT), and triphenyltin (TPhT), were determined in the sea mullet, Mugil cephalus, collected along the northern Mediterranean coast of Morocco, and the south Mediterranean coast of Spain. Also, sediment samples from the Guadalquivir River (Spain) near to its mouth in the Mediterranean Sea were analysed. TBT and TPhT were the predominant compounds in the analyzed samples, and TBT concentrations were higher in liver than in muscle. In general, the total content of BTs in these samples was higher than PT levels. In the Moroccan coast, the highest value of BTs (18.00 mg/Kg wet weight) was found in the west harbour of the Tangier site, while the lowest concentration (0.01 mg/Kg wet weight) was detected in the Oued Laoue site. Concerning PTs compounds, the highest value (4.00 mg/Kg wet weight) was found in the harbour of the M'diq Site and the lowest value (0.01 mg/Kg wet weight) was detected in the Oued Laoue site. On the other hand, organotin (OT) residues were not detected in the water samples of the Spanish coast although TBT was identified in four of the nine sediment samples from the Guadalquivir River at concentrations between 15.45 and 245.07 mg/Kg wet weight.

Certification of butyltins and phenyltins in marine sediment certified reference material by species-specific isotope-dilution mass spectrometric analysis using synthesized 118Sn-enriched organotin compounds

A new marine sediment certified reference material, NMIJ CRM 7306-a, for butyltin and phenyltin analysis has been prepared and certified by the National Metrological Institute of Japan at the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). Candidate sediment material was collected at a bay near industrial activity in Japan. After air-drying, sieving, and mixing the material was sterilized with gamma-ray irradiation. The material was re-mixed and packaged into 250 glass bottles (15 g each) and these were stored in a freezer at -30 degrees C. Certification was performed by use of three different types of species-specific isotope-dilution mass spectrometry (SSID-MS)-SSID-GC-ICP-MS, SSID-GC-MS, and SSID-LC-ICP-MS, with 118Sn-enriched organotin compounds synthesized from 118Sn-enriched metal used as a spike. The 118Sn-enriched mono-butyltin (MBT), dibutyltin (DBT), and tributyltin (TBT) were synthesized as a mixture whereas the 118Sn-enriched di-phenyltin (DPhT) and triphenyltin (TPhT) were synthesized individually. Four different extraction methods, mechanical shaking, ultrasonic, microwave-assisted, and pressurized liquid extraction, were adopted to avoid possible analytical bias caused by non-quantitative extraction and degradation or inter-conversion of analytes in sample preparations. Tropolone was used as chelating agent in all the extraction methods. Certified values are given for TBT 44+/-3 microg kg(-1) as Sn, DBT 51 +/- 2 microg kg(-1) as Sn, MBT 67 +/- 3 microg kg(-1) as Sn, TPhT 6.9 +/- 1.2 microg kg(-1) as Sn, and DPhT 3.4 +/- 1.2 microg kg(-1) as Sn. These levels are lower than in other sediment CRMs currently available for analysis of organotin compounds.

Organotin speciation in environmental matrices by automated on-line hydride generation-programmed temperature vaporization-capillary gas chromatography–mass spectrometry detection

In the present contribution, a new automated on-line hydride generation methodology was developed for dibutyltin and tributyltin speciation at the trace level, using a programmable temperature-vaporizing inlet followed by capillary gas chromatography coupled to mass spectrometry in the selected ion-monitoring mode acquisition (PTV-GC/MS(SIM)). The methodology involves a sequence defined by two running methods, the first one configured for hydride generation with sodium tetrahydroborate as derivatising agent and the second configured for speciation purposes, using a conventional autosampler and data acquisition controlled by the instrument's software. From the method-development experiments, it had been established that injector configuration has a great effect on the speciation of the actual methodology, particularly, the initial inlet temperature (-20 degrees C; He: 150 ml/min), injection volume (2 microl) and solvent characteristics using the solvent venting mode. Under optimized conditions, a remarkable instrumental performance including very good precision (RSD < 4%), excellent linear dynamic range (up to 50 microg/ml) and limits of detection of 0.12 microg/ml and 9 ng/ml, were obtained for dibutyltin and tributyltin, respectively. The feasibility of the present methodology was validated through assays upon in-house spiked water (2 ng/ml) and a certified reference sediment matrix (Community Bureau of Reference, CRM 462, Nr. 330 dibutyltin: 68+/-12 ng/g; tributyltin: 54+/-15 ng/g on dry mass basis), using liquid-liquid extraction (LLE) and solid-phase extraction (SPE) sample enrichment and multiple injections (2 x 5 microl) for sensitivity enhancement. The methodology evidenced high reproducibility, is easy to work-up, sensitive and showed to be a suitable alternative to replace the currently dedicated analytical systems for organotin speciation in environmental matrices at the trace level.

Survey of organotin compounds in rivers and coastal environments in Portugal 1999-2000

In the period from April 1999 to May 2000, organotin pollution, namely butyl and phenyltins, was investigated in coastal and continental waters (46 stations), estuarine sediments (15 stations) and mussels (Mytilus galloprovincialis) (13 stations) throughout Portugal. Sampling points were chosen in areas of specific industrial, agricultural and harbor activities. Butyltins (BTs) were the only tin species identified of which tributyltin (TBT) was found in the whole area. Concentrations of TBT in river water ranged from 3 to 30 ng L(-1) (as Sn), marine sediment ranged from 4 to 12 microg kg(-1) (as Sn), whereas concentrations in mussel tissue ranged from 2.5 to 490 microg kg(-1) (as Sn). Given that some water samples appeared to be contaminated by higher monobutyltin (MBT) and dibutyltin (DBT) concentrations, the role of biological degradation and direct inputs from agricultural and industrial applications areas are discussed. The study compares depleted butyltin pollution in sediments and mussels of the Portuguese coastline associated with antifouling paints with previously reported levels. Inputs in river waters are more related to (i) PVC leaching and (ii) industrial sources, in some cases discharged by municipal wastewaters.

Effects of gamma-sterilization on butyltin homogeneity and content in sediments: a GC-ICP-MS study

A GC-ICP-MS method based on extraction and alkylation of butyltins with sodium tetraethylborate was used to quantitatively assess the fate of these analytes in solutions and sediments following exposure to gamma-irradiation. The effects of a 2.5 Mrad sterilization dose on three butyltin species in both methanolic calibration solutions and in sediment matrices were investigated. Although significant losses of tributyltin (TBT, 90%), dibutyltin (DBT, 100%) and monobutyltin (MBT, 80%) were detected in standard solutions prepared in methanol following gamma-irradiation, no species inter-conversion occurred. Some degradation of TBT (38%) and DBT (32%) but no significant change in MBT content was found using a spiked sediment CRM HISS-1. Conversion DBT to MBT in spiked HISS-1 was deduced. Much smaller degradation of TBT (16% loss) and 10% loss of DBT by conversion to MBT (14% gain) was registered using a sediment blend of PACS-2 and HISS-1 (SOPH). Despite some initial losses of TBT and DBT due to irradiation, better than 2% RSD in both TBT and DBT concentrations measured in twelve different bottles of blended sediment SOPH were obtained, indicating the material may be considered homogeneous for these analytes. Results from a long-term five-year stability study of PACS-2 show that all three butyltins are stable during storage at 4 degrees C followed with 2.5 Mrad minimum dose of gamma-irradiation sterilization treatment.