Refinar búsqueda
Resultados 1-10 de 30
Accumulation of anticoagulant rodenticides in a non-target insectivore, the European hedgehog (Erinaceus europaeus)
2010
Dowding, Claire V. | Shore, Richard F. | Worgan, Andrew | Baker, Philip J. | Harris, Stephen
Studies on exposure of non-targets to anticoagulant rodenticides have largely focussed on predatory birds and mammals; insectivores have rarely been studied. We investigated the exposure of 120 European hedgehogs (Erinaceus europaeus) from throughout Britain to first- and second-generation anticoagulant rodenticides (FGARs and SGARs) using high performance liquid chromatography coupled with fluorescence detection (HPLC) and liquid-chromatography mass spectrometry (LCMS). The proportion of hedgehogs with liver SGAR concentrations detected by HPLC was 3–13% per compound, 23% overall. LCMS identified much higher prevalence for difenacoum and bromadiolone, mainly because of greater ability to detect low-level contamination. The overall proportion of hedgehogs with LCMS-detected residues was 57.5% (SGARs alone) and 66.7% (FGARs and SGARs combined); 27 (22.5%) hedgehogs contained >1 rodenticide. Exposure of insectivores and predators to anticoagulant rodenticides appears to be similar. The greater sensitivity of LCMS suggests that hitherto exposure of non-targets is likely to have been under-estimated using HPLC techniques. Exposure of insectivorous hedgehogs to anticoagulant rodenticides in Britain is similar to predatory birds and mammals that specialise in eating small mammals, and hitherto exposure levels have been under-estimated using HPLC techniques.
Mostrar más [+] Menos [-]Persistent organic pollutants (PCB, DDT, HCH, HCB & BDE) in eels (Anguilla anguilla) in Scotland: Current levels and temporal trends
2010
Macgregor, Kenneth | Oliver, Ian W. | Harris, Lynsay | Ridgway, Ian M.
Eels are an ideal biomonitor for persistent organic pollutants (POPs) because of their high lipid content, longevity and tendency to remain within a defined range during their freshwater life phase. This study investigated concentrations of POPs in eels (Anguilla anguilla) from 30 sites across Scotland, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (BDEs), DDT (and metabolites), hexachlorocyclohexanes (α, β, γ-HCH), hexachlorobenzene (HCB), hexachlorobutadiene (HCBD) and pentachlorobenzene. Despite its EU-wide ban ∼30 years ago, DDT and its derivatives were detected in almost all samples. PCB 153 and 138 were the most widely detected PCB congeners, while BDE 47 was the dominant BDE. Pentachlorobenzene was not detected, while HCBD was detected once only. α-HCH, β-HCH and HCB concentrations were very low (generally <3 μg/kg or below detection). When compared with 1986 and 1995 data, the results revealed considerable decreases in p,p′-DDE concentrations. More drastic reductions were evident for γ-HCH, reflecting the tightening restrictions on pesticide use imposed over the previous decades.
Mostrar más [+] Menos [-]Dissipation and metabolism of 14C-spiroxamine in soil under laboratory condition
2010
Sukul, Premasis | Zühlke, Sebastian | Lamshöft, Marc | Rosales-Conrado, Noelia | Spiteller, M (Michael)
Spiroxamine [SPX] belongs to a spiroketalamine group of substances. The biodegradation of [1,3-dioxolane-4-14C]-SPX has been examined in 2 soils of different physicochemical properties. The total recovery of radioactivity from soils was 98.6-103.5% of that applied. The total amount of extractable radioactivity declined with a simultaneous increase in non-extractable radioactivity. Volatile organics were detected at lower levels; however, mineralization played a marked effect on the route of SPX dissipation. The half-life ranges between 37 and 44 d. SPX does not undergo any enantioselective degradation. 4 metabolites: despropyl-SPX, desethyl-SPX, SPX N-oxide and SPX acid were identified, applying mass spectrometric technique. Sorption-desorption data fitted well with a Freundlich model in log form (r2, 0.99). KDsorp ranged between 44 and 230, suggesting SPX ought to be considered as a substance with low leaching potential [groundwater ubiquity score (GUS), <1.8]. Furthermore, an overall low desorption of 1–11% indicates firm retention of SPX by the soils.
Mostrar más [+] Menos [-]Detection of free and covalently bound microcystins in animal tissues by liquid chromatography-tandem mass spectrometry
2010
Neffling, Milla-Riina | Lance, Emilie | Meriluoto, Jussi
Microcystins are cyanobacterial hepatotoxins capable of accumulation into animal tissues. The toxins act by inhibiting specific protein phosphatases and both non-covalent and covalent interactions occur. The 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB) method determines the total, i.e. the sum of free and protein-bound microcystin in tissues. The aim of the method development in this paper was to tackle the problems with the MMPB methodology: the rather laborious workflow and the loss of material during different steps of the method. In the optimised workflow the oxidation recovery was of acceptable level (29–40%), the extraction efficiency good (62–97%), but the signal suppression effect from the matrix remained severe in our system (16–37% signal left). The extraction efficiency for the determination of the free, extractable microcystins, was found to be good, 52–100%, depending on the sample and the toxin variant and concentration. The study concerns method development for the LC–MS–MS analysis of both free and protein-bound microcystin in tissue materials.
Mostrar más [+] Menos [-]Determination of antibiotics in sewage from hospitals, nursery and slaughter house, wastewater treatment plant and source water in Chongqing region of Three Gorge Reservoir in China
2010
Chang, Xiaosong | Meyer, Michael T. | Liu, Xiaoyun | Zhao, Qing | Chen, Hao | Chen, Ji-an | Qiu, Zhiqun | Yang, Lan | Cao, Jia | Shu, Weiqun
Sewage samples from 4 hospitals, 1 nursery, 1 slaughter house, 1 wastewater treatment plant and 5 source water samples of Chongqing region of Three Gorge Reservoir were analyzed for macrolide, lincosamide, trimethoprim, fluorouinolone, sulfonamide and tetracycline antibiotics by online solid-phase extraction and liquid chromatography-tandem mass spectrometry. Results showed that the concentration of ofloxacin (OFX) in hospital was the highest among all water environments ranged from 1.660 μg/L to 4.240 μg/L and norfloxacin (NOR, 0.136-1.620 μg/L), ciproflaxacin (CIP, ranged from 0.011 μg/L to 0.136 μg/L), trimethoprim (TMP, 0.061-0.174 μg/L) were commonly detected. Removal range of antibiotics in the wastewater treatment plant was 18–100% and the removal ratio of tylosin, oxytetracycline and tetracycline were 100%. Relatively higher removal efficiencies were observed for tylosin (TYL), oxytetracycline (OXY) and tetracycline (TET)(100%), while lower removal efficiencies were observed for Trimethoprim (TMP, 1%), Epi-iso-chlorotetracycline (EICIC, 18%) and Erythromycin-H2O (ERY-H2O, 24%). Antibiotics were removed more efficiently in primary treatment compared with those in secondary treatment.
Mostrar más [+] Menos [-]A simple inexpensive gas phase chemiluminescence analyzer for measuring trace levels of arsenic in drinking water
2010
Sengupta, Mrinal K. | Hossain, Zafreen A. | Ohira, Shin-Ichi | Dasgupta, Purnendu K.
An inexpensive sensitive gas-phase chemiluminescence (GPCL) based analyzer for arsenic is described; this device utilizes manual fluid dispensing operations to reduce size, weight and cost. The analyzer in its present form has a limit of detection (LOD, S/N = 3) of 1.0 μg/L total inorganic As (peak heightbased, 3 mL sample). The system was used to measure low level arsenic in tap water samples from Texas and New Mexico and compared with results obtained by inductively coupled plasma-mass spectrometry (ICP-MS) as well as those from an automated GPCL analyzer. Good correlations were observed. Higher levels of As (50–500 μg/L, As(III), As(V) and mixtures thereof) were spiked into local tap water; the recoveries ranged from 95 ± 2% to 101 ± 1%. A single instrument weighs less than 3 kg, consumes <25 W in power, can be incorporated in a briefcase and constructed for <$US $1000. It is easily usable in the field. An inexpensive instrument capable of measuring down to 1 μg/L As is reported.
Mostrar más [+] Menos [-]Prediction of the PCDD/F and dl-PCB 2005-WHO-TEQ content based on the contribution of six congeners: Toward a new screening approach for fish samples
2010
Cariou, Ronan | Marchang, Philippe | Vénisseau, Anaïs | Brosseaud, Aline | Bertrand, Dominique | Qannari, El Mostafa | Antignac, Jean-Philippe | Le Bizec, Bruno
Current European Union regulation regarding polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in food and feed is based on Toxic Equivalent Quotient (TEQ) concept. For confirmatory purpose, the isotope-dilution method associated to a measurement by gas chromatography coupled with high resolution mass spectrometry is usually the method of choice for precisely measuring the 29 target congeners in three separated fractions. Time and cost related to these analyses are very significant. Various kinds of screening concepts can be considered. In the present study, we elaborated and validated a prediction model for the 2005 World Health Organization TEQ in fish, based on the measurement of 4 PCDD/F and 2 non-ortho dl-PCB congeners, potentially analyzable in a single extracted fraction by gas chromatography coupled with mass spectrometry. Large independent datasets have been used for model elaboration (n = 108) and validation (n = 363, n = 357 and n = 6). This study describes a statistical regression model approach for screening PCDD/Fs and dl-PCBs in fish.
Mostrar más [+] Menos [-]Uptake of Cd(II) and Pb(II) by microalgae in presence of colloidal organic matter from wastewater treatment plant effluents
2010
Worms, Isabelle A.M. | Traber, Jacqueline | Kistler, David | Sigg, Laura | Slaveykova, Vera I.
The present study addresses the key issue of linking the chemical speciation to the uptake of priority pollutants Cd(II) and Pb(II) in the wastewater treatment plant effluents, with emphasis on the role of the colloidal organic matter (EfOM). Binding of Cd(II) and Pb(II) by EfOM was examined by an ion exchange technique and flow field-flow fractionation coupled to inductively coupled plasma mass spectrometry in parallel to bioassays with green microalga Chlorella kesslerii in ultrafiltrate (<1 kDa) and colloidal isolates (1 kDa to 0.45 μm). The uptake of Cd by C. kesslerii was consistent with the speciation analysis and measured free metal ion concentrations, while Pb uptake was much greater than that expected from the speciation measurement. Better understanding of the differences in the effects of the EfOM on Cd(II) and Pb(II) uptake required to take into account the size dependence of metal binding by EfOM. Colloids isolated from WWTP effluents decrease Cd uptake, but increase Pb uptake by microalga Chlorella kesslerii.
Mostrar más [+] Menos [-]Colloidal gold probe-based immunochromatographic assay for the rapid detection of lead ions in water samples
2010
Tang, Yong | Zhai, Yi-Fan | Xiang, Jun-Jian | Wang, Hong | Liu, Bin | Guo, Chang-Wei
One-step immunochromatographic assay (ICA) has been developed using colloidal gold-labeled monoclonal antibody probe for the rapid detection of lead ions in water samples. The ICA was based on the theory of competitive reactivity, and the results can be easily judged based on the presence or absence of a red colored test line with visual detection. Under optimal conditions, this method shows high detecting sensitivity with a LOD (limit of detection) of 50 ng/ml. Stability test indicates that the immunochromatographic strips are stable for 8 weeks at room temperature. During practical application, nanometer TiO2 is used to enrich the lead ions in water samples. The ICA is successfully applied in the measurement of lead ion concentrations in local water samples, and the results are highly consistent with that of ICP-MS. Detecting lead ions with ICA can be done within 4 min and is very useful for the rapid onsite testing.
Mostrar más [+] Menos [-]Mercury and Methylmercury in Freshwater Fish and Sediments in South Korea Using Newly Adopted Purge and Trap GC-MS Detection Method
2010
Park, Jae-Sung | Lee, Jung-Sub | Kim, Gun-Bae | Cha, Jun-Seok | Shin, Sun Kyoung | Kang, Hak-Gu | Hong, Eun-Jin | Chung, Gi-Taeg | Kim, Young-Hee
The use of purge and trap gas chromatography–mass spectrometry (GC-MS) technique for the determination of methylmercury in biological and sediment samples was described. The GC-MS detection system was combined with the dithizone extraction method for biological samples and the distillation method for sediment samples to alleviate matrix interference problems. The method was validated by analysis of CRMs such as SRM 966 (human blood), BCR 463 (tuna fish), IAEA 407 (fish), ERM CC580 (estuarine sediment), and IAEA 405 (sediment). The performance of the purge and trap GC-MS method was also tested on field samples of freshwater fish and sediment. The results were compared with those of the GC-ECD and the GC-CVAFS, which were used widely for methylmercury analysis. Additionally, total mercury and methylmercury levels in freshwater fish and sediments from various reservoirs and streams in Korea were measured to understand mercury contamination status in Korean peninsula. Methylmercury concentrations in freshwater fish were found to correlate with body weight, diet habit, and food availability. In sediment, total mercury concentrations correlated with methylmercury concentrations and organic matter such as %C and %S. However, no significant relationships between methylmercury and sediment organic matter have been found.
Mostrar más [+] Menos [-]