Suchergebnisse

Over the past fifteen years regulatory agencies have relied on their approaches to characterise and control the release of toxic substances into the aquatic environment: a GC/MS analysis for U.S. EPA designated 126 priority pollutants and 132 dangerous substances according to the European 76/464/CEE Directive and on the bioassays with aquatic bioorganisms."Emerging Contaminants" correspond in most cases to irregulated contaminants, e.g. surfactants, pharmaceuticals and personal care products (PPCP), or gasoline additives.These two volumes, 5/I and 5/O, of this Handbook deal with the analytical, toxicological and environmental issues of these toxicants. Based on results of up-to-date research they give the reader a balanced view on this rapidly developing and complex subject

First European interlaboratory study of the analysis of benzoxazinone derivatives in plants by liquid chromatography (Eljarrat, E.; Guillamón, M.; Seuma, J.; Mogensen, B. B.; Fomsgaard, I. S.; Oliveros Bastidas, Alberto; Macías, F. A.; Stochmal, A.; Oleszek, W.; Shakaliene, O.; Barceló, D.) Abstract Six laboratories from four different countries participated in the first European interlaboratory comparison exercise within the framework of the "Fate and toxicity of allelochemicals (natural plant toxins) in relation to environment and consumer" (FATEALLCHEM) European Union Project. The study, organized between November 2002 and March 2003, involved the analyses of seven benzoxazinone derivatives in two standard solutions and one purified extract of root material. Results are reported from the first phase of the study that examined the variability associated with different detection methods and different laboratories. The analytical strategies were based on liquid chromatography (LC) with diode array detection, LC coupled to mass spectrometry (MS) and LC coupled to tandem MS. When data from all laboratories were pooled, the relative standard deviation values ranged from 2 to 14% for the determination of target compounds in standard solutions, and between 19 and 47% for the analysis in root material. Comparison of the three detection techniques leads to the conclusion that MS approaches are the most accurate and precise techniques for the determination of benzoxazinone derivatives at ng/µL level in plant material. © 2004 Elsevier B.V. All rights reserved. This article was presented at the 3rd Meeting of the Spanish Association of Chromatography and Related Techniques and the EuropeanWorkshop: 3rdWasteWater Cluster, Aguadulce (Almeria), 19-21 November, 2003. ; eeeqam@cid.csic.es ; aloliver@ula.ve ; famacias@uca.es ; Nivel monográfico

© 2016 American Chemical Society. Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant concentrations - where observing outcomes is difficult - versus higher ENM doses, where responses are observable. What exposure conditions are typically used in assessing ENM hazards to populations? What conditions are used to test ecosystem-scale hazards? What is known regarding actual ENMs in the environment, via measurements or modeling simulations? How should exposure conditions, ENM transformation, dose, and body burden be used in interpreting biological and computational findings for assessing risks? These questions were addressed in the context of this critical review. As a result, three main recommendations emerged. First, researchers should improve ecotoxicology of ENMs by choosing test end points, duration, and study conditions - including ENM test concentrations - that align with realistic exposure scenarios. Second, testing should proceed via tiers with iterative feedback that informs experiments at other levels of biological organization. Finally, environmental realism in ENM hazard assessments should involve greater coordination among ENM quantitative analysts, exposure modelers, and ecotoxicologists, across government, industry, and academia.