Previous lectures (2011-)
22. October 2012, 3 p.m. , KUBUS, hall 2
eawag, Environmental Chemistry, Dübendorf, Switzerland
Characterisation of treated wastewater using high resolution mass spectrometry – extending the boundaries of non-target screening
LC-MS technologies have opened the analytical window to thermolabile, polar compounds within the last 15 years. As a result, polar organic micropollutants such as pharmaceuticals have moved increasingly into the focus of environmental scientists, regulatory agencies, and politicians. To meet the analytical challenges of a mixture of many known and unknown compounds at low concentrations in complex matrices such as wastewater, the coupling of LC to high resolution mass spectrometry (HRMS) with high mass accuracy following electrospray ionization (ESI) is becoming increasingly popular.
In this presentation, the features, advantages, and limitations of LC coupled to HRMS for three conceptually different approaches are illustrated by selected studies in the field of wastewater treatment. These approaches include: (i) quantitative target analysis with reference standards; (ii) suspects screening without reference standards; and (iii) non target screening for unknowns.
In contrast to target and suspects screening, non-target (unknown) screening in a strict sense starts without any a priori information on the compounds to be detected. A tentative identification of non-target analytes in environmental samples with unconstrained boundary conditions is challenging and a structure proposition for a detected peak by high resolution MS and MS/MS spectra involves several work-intensive data and expert processing steps. The workflow involves peak detection by exact mass filtering from the chromatographic run, assignment of an elemental formula to the exact mass of interest, and data base searches for plausible structures for the determined elemental formula.
Especially municipal waste water contains a vast array of organic pollutants even after advanced treatment which may cause adverse effects in the aquatic environment. Characterising the presence of organic micropollutants in wastewater effluents is fraught with challenges and the full assessment of the effectiveness of treatment options is often difficult as many organic micropollutants transform during the treatment process. As a result, a pure target screening approach may indicate that a compounds is no longer present following treatment, while the compound is still present but in a transformed state. This and similar situations can be addressed using a combination of target and non-target screening approach on wastewater effluents.
Host: Tobias Schulze (WANA)
19. September 2012, 1 p.m. , KUBUS, hall 1A
AG Chemische Systembiologie, Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin
EU-OPENSCREEN, a European Infrastructure of Open-Access Screening Platforms for Chemical Biology
EU-OPENSCREEN is a research infrastructure initiative on the ESFRI roadmap (European Strategy Forum on Research Infrastructures) which aims to offer researchers from academia and SMEs access to shared instrumentation, expertise and resources for the identification of compounds affecting biological targets in all fields of the life sciences. EU-OPENSCREEN integrates high-throughput screening platforms in Europe, chemical libraries, chemical expertise and resources for discovery and optimisation, bio- and chemoinformatics support, and a database containing screening results, assay protocols, and chemical information. EU-OPENSCREEN will deliver bioactive compounds for research and for the development of new and safer products, and will increase our knowledge about how chemicals influence our lives and environment.
(Host: Rolf Altenburger)
10. May, 2012, 2 p.m. , lecture room 1st floor, building 1 (main building)
Beate I. Escher
The University of Queensland, National Research Centre for Environmental Toxicology (Entox), Brisbane QLD 4108, Australia
What’s in our water? Bioanalytical tools for assessment of micropollutants, mixtures and transformation products
Chemical pollution is an increasing threat to our waterways, oceans, and drinking water sources. The impact of chemical pollution will be amplified by population growth and, possibly, by some of the effects of climate change. However, conventional chemical monitoring programs have been criticised on the basis that they cannot include the full range of chemical pollutants that could occur in water sources, and they do not account for the combined effects of mixtures of chemicals. Bioanalytical tools may therefore complement chemical analysis for cost-efficient water quality monitoring.
Bioanalytical tools are cell-based bioassays that target specific mechanisms of toxicity and give a measure of the toxicity of mixtures of known and unknown chemicals, such as pesticides, industrial chemicals, pharmaceuticals and their transformation products. Bioanalytical tools provide measures of the cumulative effects of chemicals that exhibit the same mode of toxic action, for which the selected bioassays are indicative plus they can give a measure of the cytotoxicity of all chemicals acting together in a water sample. Improved detection of the presence of chemicals in water enhances risk assessment and informs water management options, among them water recycling from impaired sources such as sewage, coal seam gas water, or stormwater harvesting and reuse.
In this presentation the design of a modular battery of bioassays will be presented and some illustrative examples from recent applications in South East Queensland, Australia. The bioassays were selected from the three main categories of modes of action, namely non-specific, receptor-mediated specific and reactive toxicity. This bioanalytical test battery was used for monitoring organic micropollutants and disinfection by-products across an indirect potable reuse scheme testing sites across the complete water cycle from sewage to drinking water to assess the efficacy of different treatment barriers, including source control, wastewater treatment plant, microfiltration, reverse osmosis, advance oxidation, natural environment in a reservoir and drinking water treatment plant.
Professor Beate Escher is Deputy Director of the National Research Centre for Environmental Toxicology (Entox) in Brisbane, Australia, which is a joint venture between the University of Queensland and Queensland Health. Beate Escher received her PhD in Environmental Chemistry from the Swiss Federal Institute of Technology in Zürich, ETHZ, Switzerland. In 2002 she completed her habilitation in Environmental Toxicology and Chemistry ETHZ. She held a previous appointment as group leader at the Swiss Federal Institute of Aquatic Science, Eawag, in Dübendorf, Switzerland and was lecturer at ETHZ. Her research interests focus mode-of-action based environmental risk assessment, including methods for initial hazard screening and risk assessment of pharmaceuticals and pesticides, environmental transformation products, and mixtures. More practically oriented aspects of her work include passive sampling and effect-based methods for water quality assessment.
2. December 2011, KUBUS hall 1CD, 1 p.m.
Dr. Rudolf J. Schneider, BAM Bundesanstalt für Materialforschung und -prüfung, Berlin
Immunoanalytical methods for the environmental sciences
Immunoanalytical methods owe their selectivity and sensitivity to antibodies. Environmentally relevant substances, i.e. pollutants, are usually not immunogenic. Still it is possible to generate antibodies against them by using derivatives coupled to large carrier proteins. Selectivity always and in many cases sensitivity, too, depends on the structure of these immunogens. Having developed the antibodies, conjugates, such as enzyme tracers for enzyme immunoassays, are needed for the establishment and optimization of the different immunoassay formats.
We developed immunochemical methods for the determination of pesticides (atrazine, terbuthylazine), hormones or endocrine disruptors, respectively (estradiol, ethinylestradiol), pharmaceuticals (sulfamethoxazole, carbamazepine) and anthropogenic markers (caffeine, coprostanol). In the lecture examples are described how these assays have been applied for environmental research, e.g. in the screening of soil extracts for pesticide application, determination of hormones in wastewater and monitoring of carbamazepine and caffeine in surface waters. By coupling liquid chromatography to immunochemical detection we developed a tool for non-target screening which led to the identification of cetirizine in many surface water samples.
The lecture will end with a look at the pros and cons of immunoassays and will hopefully lead into a discussion on the potential and constraints of immunoanalytical methods in environmental sciences.
(Host: Martin Krauss, Department Effect directed analysis)
22. June 2011, KUBUS hall 2, 3 p.m.
Dr. Markus Meringer, German Aerospace Centre (DLR), Earth Observation Center (EOC)
Molecular Structure Generation and its Potential for Environmental Analytics
Structure generation algorithms are an important means to construct virtual chemical compound spaces on the level of constitutions. In this presentation some of the most essential principles of exhaustive and non-redundant structure enumeration will be reviewed: starting from simple labeled graphs we will see how to avoid isomorphic duplicates, introduce structural constraints and how to generate molecular graphs in an efficient way.
As an application structure generators provide candidate structures for approaches towards automated structure elucidation. In environmental analytics such approaches are often based on mass spectrometry measurements. Some recent developments in this area will be summarized.
(Host: Werner Brack, Department Effect directed analysis
21. March 2011, KUBUS hall 2, 10 a.m.
Inge Werner, Schweizer Zentrum für angewandte Ökotoxikologie
Toxic effects of pyrethroid insecticides in non-target aquatic organisms.
Pyrethroid insecticides are widely used in agriculture and residential
pest control. In recent years, they have been identified as pollutants
in water and sediments of surface water bodies in California and
elsewhere. Measurement of these hydrophobic and relatively short-lived,
but highly toxic chemicals can present considerable challenges with
respect to adsorption to sampling equipment, and degradation during
sample storage, while analytical detection limits in water samples (1-3
ng/l) are in the range of biological effect concentrations for sensitive
aquatic invertebrates. Measured surface water concentrations are in a
range where ecological fitness of fish may be impaired indirectly by the
depletion of invertebrate prey, and directly by sublethal toxic effects
on behavior or immune responses. This presentation will provide an
overview of known toxic effect levels of pyrethroids in aquatic species,
as well as information on their sublethal effects in fish.
(Host: Matthias Liess, Department Systems Ecotoxicology
4. March 2010, Room to be announced soon, 10 a.m.
Lisa Schulze, Universität Trier
Brutpflege bei Pfeilgiftfröschen - auf der Suche nach chemischen Signalstoffen bei Kaulquappen
Elterliche Brutpflege ist bei evolutiv hoch entwickelten Anuren weit verbreitet. Viele Aspekte, die dieses Verhalten beeinflussen sind dabei jedoch noch weitestgehend unerforscht.
Der in Peru endemische Pfeilgiftfrosch Ranitomeya variabilis (Dendrobatidae) ist dazu in der Lage, zu erkennen, ob ein von diesen Tieren für die Larvenaufzucht genutztes Kleinstgewässer (Phytotelm) bereits von einer anderen Larve besetzt ist oder nicht. Besetzte Phytotelmata werden für die Aufzucht des eigenen Nachwuchses gemieden, da die Kaulquappen untereinander kannibalistisch sind. Wir konnten herausfinden, dass eine solche Meidung durch den Frosch anhand von chemischen Signalstoffen erfolgt. Dabei konnten wir zeigen, dass die Tiere hierbei sogar zwischen Kaulquappen verschiedener Arten differenzieren können. Das führt uns zu folgender Theorie: Die von R. variabilis gemiedenen Larven produzieren entweder eine spezielle Substanz, die über den Exkretionsmetabolismus abgegeben wird und sie von anderen Anurenlarven unterscheidet, oder eine solche Substanz befindet sich in über die Haut abgegebenen Drüsensekreten.
Aus diesem Grund planen wir, eine wirkungsorientierte Analytik der von den Kaulquappen abgegebenen Signalstoffe durchzuführen, um herauszufinden, an welchen Stoffen sich die Adulti bei ihrer Wahl der Phytotelmata orientieren.
(Host: Werner Brack, Department Effect-Directed Analysis)