Einar Magne Brevik

Quantification of organotin compounds and determination of imposex in populations of dogwhelks (Nucella lapillus) from Norway

Unintentional effects of the antifouling agent tributyltin (TBT) have been discovered in marine gastropods as the induction of male sex characters in females, known as imposex. The occurrence of imposex in dogwhelks (Nucella lapillus) was investigated in 41 populations sampled in 1993-1995 along the Norwegian coast. A method for quantification of organotin species using gas chromatography and atomic emission detection (GC-AED) was developed. Some degree of imposex occurred in almost all populations of dogwhelks studied, except in four from Northern Norway. The concentration of organotin compounds in the gastropods from the unaffected populations was below the detection limit (7 ng Sn/g d.w.). The concentration of TBT in dogwhelks from affected populations was in the range 48-1096 ng Sn/g d.w. A positive relation between the concentration of TBT in dogwhelks and the degree of imposex was found.

Organotins in marine mammals and seabirds from Norwegian territory.

An increasing number of studies indicate that marine mammals and some seabirds are exposed to organotins. However, results from northern and Arctic areas are few. Here results from analysis of tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT) in harbour porpoise (Phocoena phocoena), common seal (Phoca vitulina), ringed seal (Phoca hispida) and glaucous gull (Larus hyperboreus) from Norwegian territory are presented. Relatively high concentrations of DBT, TBT and MBT were observed in muscle, kidney and liver from harbour porpoises caught in northern Norway in 1988, just before restrictions on the use of tributyltin (TBT)(mainly on small boats) were introduced in several European countries. The concentrations in harbour porpoise muscle tissue were reduced significantly 11 years later, possibly as a result of the introduced restrictions. Considerably lower concentrations of butyltins were observed in the seals compared to porpoises. The lowest levels of organotins were found in ringed seals from Spitsbergen, where only traces of dibutyltin (DBT) and monobutyltin (MBT) were observed. Traces of DBT and MBT were also found in some individual glaucous gulls from Bear Island. The sum of the degradation products MBT and DBT in liver samples from all analysed species were generally higher than TBT itself. Triphenyltin (TPhT) was observed in all porpoise samples and in livers of common seals. Also the sum of the degradation products MPhT and DPhT in liver samples from porpoise and common seals were higher than TPhT. No traces of phenyltins were found in ringed seals from Spitsbergen or in glaucous gulls from Bear Island. The limited data available indicate low to moderate exposure to organotins in northern areas (Spitsbergen and Bear Island). Marine mammals are however more exposed further south along the Norwegian Coast.

Comparison of GC-ECD, GC-MS and GC-AED for the determination of polychlorinated biphenyls in highly contaminated marine sediments

SummaryElectron capture detection (ECD), low- and highresolution mass spectrometry (LR- and HRMS), and atomic emission detection (AED) were compared for the gas chromatographic (GC) detection of polychlorinated biphenyls (PCBs) present in highly contaminated marine sediments. With ECD, LRMS, and even HRMS, detection was seriously disturbed by the complex matrix of the sediments, whereas AED in the chlorine-selective mode provided excellent PCB profiles without interferences. In addition, GC-AED provided congener independent responses, which enabled accurate quantitation of all PCBs based on a single calibration curve. However, because GC-AED was less sensitive than the other techniques studied, preparation of relatively large amounts of sample (10–20 g dry sediment) was required for most analyses.

Monitoring of organotin compounds in seawaterusing semipermeable membrane devices (SPMDs)—tentative results

The impact of anthropogenic pollutants on the marine ecosystem is related to the concentrations experienced by the biota in the seawater and the resulting concentration in the organism. Results from monitoring of pollutants in water samples provide snapshots that can be high or low depending on a wide range of variables. To provide more integrated information, semipermeable membrane devices, SPMDs, have been used to monitor different organic pollutants. In this survey, SPMDs were used to monitor organotin compounds in the marine environment. Time-integrated sampling using SPMDs and direct water sampling was carried out at six stations in the inner Oslofjord, Norway. The sample work-up procedure for both water and SPMDs was based on direct derivatisation using NaBEt4 and simultaneous extraction with an organic solvent. Analysis was performed using a gas chromatograph equipped with an atomic emission detector. The results show that SPMDs do accumulate organotin compounds from the water phase. Both tributyl- (TBT) and dibutyltin were detected in all of the analysed membranes while no monobutyltin was found. Levels found in SPMDs range from < 1 to 220 ng Sn SPMD(-1). Water concentrations range from 0.4 to 10 ng Sn L(-1). An investigation of relative levels of TBT showed a similar concentration gradient in the inner Oslofjord using either direct water sampling or passive sampling by SPMDs. As the membranes are able to accumulate the organotins from the water it will be possible to locate lower concentrations than with direct analyses of water samples.

Organotin compounds in a Norwegian fjord. A comparison of concentration levels in semipermeable membrane devices (SPMDs), blue mussels (Mytilus edulis) and water samples

Monitoring concentrations of organic pollutants in water is essential to predict effects and to initiate preventive steps. Results from the analysis of water samples provide snapshots of a situation, whereas monitoring using semipermeable membrane devices (SPMDs) provides a time-integrated picture of the concentration of pollutants in water. In this investigation, SPMDs, caged mussels and water samples were used to monitor the levels of organotin compounds in the inner Oslofjord, Norway, over a period of 12 weeks. The work-up procedure for the analysis of organotins was optimised, focusing on the clean-up procedure using gel permeation chromatography (GPC). By using several GPC columns, as much as 1 g of triolein could be employed. This reduces the background emission noise on the baseline, leading to an improvement in the detection limits. The main uptake of tributyltin (TBT) in mussels and SPMDs levelled off after 14 days. A longer uptake period was indicated for SPMDs at stations with a high water concentration of TBT (5-10 ng Sn L(-1)) compared with those with a low water concentration of TBT (approximately 1 ng Sn L(-1)). A concentration gradient was observed for water, SPMDs and mussels from the innermost station close to Oslo harbour to the station further out in the fjord, indicating that the three analysed matrices give approximately the same pollution gradient. The bioconcentration factor (BCF) for TBT in mussels was in the range 12-14 000 (wet weight) and, for SPMDs, 10-12 000 (fat). A good correlation with the TBT water concentrations was achieved within a period of 14-30 days of exposure for mussels and after 2-3 months for SPMDs. A good correlation was also found between the TBT concentration in SPMDs and mussels at the end of the experiment. SPMDs can therefore be used to predict concentrations of TBT in both water and mussels.

Interspecies differences in tissue distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin between cod (Gadus morhua) and rainbow trout (Oncorhynchus mykiss)

The tissue distribution after administration of a single oral dose (30 μg/kg b.wt., corresponding to 12 μCi/kg b.wt.) of 14C-2,3,7,8-dibenzo-p-dioxin (14C-2,3,7,8-TCDD) was studied in cod (Gadus morhua) and sea-water adapted rainbow trout (Oncorhynchus mykiss) by means of whole-body autoradiography and liquid scintillation counting. Substantial inter-species differences in the distribution pattern were observed. The highest concentrations of 14C-2,3,7,8-TCDD derived radioactivity in the cod were found in the liver and the central nervous system, while the predilection sites for radioactivity in the rainbow trout were the visceral and extravisceral fat depots. The amounts of radioactivity in the liver and the central nervous system of the cod exceeded those of the rainbow trout by a factor of 10 and 7, respectively.

Capillary gas chromatography combined with atomic emission detection for the analysis of polychlorinated biphenyls

Abstract Capillary gas chromatography with atomic emission detection (GC-AED) was evaluated for the analysis of polychlorinated biphenyls (PCBs). Since Cl-responses were almost independent of the PCB structure, individual PCBs were quantitated with an accuracy better than 10% utilizing a Cl-calibration plot based on a single randomly selected congener (universal calibration). In addition, within a 5–10% accuracy, GC-AED enabled estimation of total PCB residue levels and calculation of the percentage by weight of chlorine in contaminating PCB mixtures. Thus, although PCB detection limits were higher with GC-AED than with GC-ECD, the former technique was very attractive for PCB investigations and enabled significant simplification of PCB quantitation.

DDT contamination of fish and sediments from Lake Orsjoen, Southern Norway: comparison of data from 1975 and 1994

Abstract Long term DDT contamination is reported of a small lake which previously was recipient of the insecticide wastes from a plant nursery. 19 years after closing down of the outfall sum-DDT in perch and pike exceeds an assumed “high background level” by about 5–10 times. Gradient studies of sediments and perch indicated that deposits in the close vicinity of the former outfall still acted as a source for contamination of the more distant parts of the lake. Comparison with 1975 data nevertheless showed that DDT levels in fish had been reduced by about 90% and a rough estimate indicated a “half life” of DDT of 5–7 years.

Environmental screening by capillary gas chromatography combined with mass spectrometry and atomic emission spectroscopy

Capillary gas chromatography (GC) combined with mass spectrometry (MS) and atomic emission spectroscopy (AED) was utilized for a comprehensive investigation of organic micropollutants in a marine sediment. Most compounds were found and identified by GC-MS library search. The elemental information from GC-AED was utilized for confirmation purposes, for analyte characterization in cases where identification by GC-MS was impossible, and for screening on heteroatomic components. In addition, GC-AED was effectively used for the quantitative part, where the total amount of GC amenable material, classes of compounds, and individual components were determined.

Solid-phase microextraction coupled with atomic emission spectroscopy––rapid screening for volatile chlorinated compounds

Solid-phase microextraction (SPME) coupled with atomic emission spectroscopy was evaluated as a rapid screening tool for volatile halogenated compounds in water samples. After extraction, the SPME fiber was introduced to the injector where the analytes were rapidly and efficiently desorbed. The analytes entered the detector over a short period of time and produced one well-defined analyte signal. Element selective responses were measured to confirm the presence and to roughly estimate the content of volatile compounds. The total time for extraction and detection was approximately 5 min, which makes this method a rapid and promising technique for determination of total amount of volatile halogenated compounds. The proposed technique may prove useful as a screening test in order to pinpoint the samples that need further assessment by capillary gas chromatography.