TY - CONF A1 - Walther, Wolfgang A1 - Becker, Roland A1 - Nehls, Irene A1 - Lehmann, Andreas A1 - Redlich, Christel A1 - Flemig, Sabine A1 - Dorgerloh, Ute A1 - Win, Tin A1 - Buge, Hans-Gerhard T1 - Pentchlorophenol (PCP) in Soil - Certified Reference Materials for Environmental Analysis T2 - Analytica Conference 2002 CY - Munich, Germany DA - 2002-04-23 PY - 2002 SP - 1(?) AN - OPUS4-1389 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Schwarzer, Martin A1 - Becker, Roland A1 - Kuhnhardt, Claus A1 - Nehls, Irene T1 - Methodenvergleich zur Bestimmung von extrahierbaren organischem Halogen (EOX) in Bodenproben N2 - Ziel der vorliegenden Untersuchungen, die im Rahmen einer Diplomarbeit der Fachhochschule Lausitz/Senftenberg an der BAM durchgeführt wurden, war ein Vergleich unterschiedlicher Extraktionsverfahren für die Bestimmung von extrahierbarem organischem Halogen (EOX) in Bodenproben. EOX ist ein für die rasche Bewertung der Organochlor- Belastung kontaminationsverdächtiger Flächen wertvoller Summenparameter, der sämtliche mit organischen Lösungsmittel extrahierbare Organohalogenverbindungen erfasst. Gegenwärtig existiert jedoch kein für die Bodenanalytik genormtes Verfahren für die Durchführung von EOX-Bestimmungen. Daher wird in der Praxis auf das für Schlämme und Sedimente entwickelte Verfahren nach DIN 38414 S17 (1990) zurückgegriffen, so auch in der Bundesbodenschutz- und Altlasten-Verordung (BBodSchV). Literaturangaben und Erfahrungen mit der Wiederfindungsrate polarer Extraktionsmittel und moderner Extraktionsverfahren bei Organochlorpestiziden, die eine bedeutende Quelle für EOX in Schlämmen und Böden darstellen, lassen vermuten, dass das genannte Normverfahren systematisch zu Unterbefunden neigen könnte. Für die Untersuchungen wurden an der BAM entwickelte Boden-Referenzmaterialien mit "natürlicher", über jahrzehntelangen Eintrag entstandener DDT- und Lindan-Belastung verwendet. Neben den klassischen Extraktionsverfahren nach Soxhlet kamen die ultraschallunterstützte Extraktion, die Mikrowellen- und die beschleunigte Lösungsmittelextraktion (ASE) jeweils mit Lösungsmitteln unterschiedlicher Polarität zum Einsatz. Extraktionsausbeuten und Wiederholpräzision der einzelnen Varianten wurden verglichen und vor dem Hintergrund der Ergebnisse unabhängiger Verfahren wie der gaschromatographischen Bestimmung der einzelnen Organochlorverbindungen bewertet. Die Polarität des Extraktionsmittels weist auch bei trockenen Böden den größten Einfluss auf die Extraktionsausbeuten der in den untersuchten Proben enthaltenen Organochlorverbindungen auf. Die Mischung Hexan/Aceton (1:1), die sich für die Extraktion verschiedener organischer Parameter bewährt hat, ist hinsichtlich der EOX-Analytik der existierenden Norm überlegen. T3 - BAM Forschungsberichtreihe - 263 PY - 2003 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-1884 SN - 978-3-86509-083-4 SN - 0938-5533 VL - 263 SP - 1 EP - 64 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schultze, Karin A1 - Philipp, Rosemarie A1 - Redlich, Christel A1 - Dorgerloh, Ute A1 - Becker, Roland A1 - Win, Tin A1 - Nehls, Irene T1 - Development, preparation and certification of a reference material for the determination of chlorinated pesticides in soil T2 - Symposium "Reference Materials for Technologies in the New Millenium" CY - Berlin, BAM, Germany DA - 2000-05-22 PY - 2000 SP - 1(?) EP - 4(?) AN - OPUS4-1313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schultze, Karin A1 - Nehls, Irene A1 - Bremser, Wolfram A1 - Becker, Roland A1 - Win, Tin T1 - Zertifiziertes Referenzmaterial "BAM-U007" - Organochlorpestizide in Boden T2 - ANAKON 2001 CY - Konstanz, Germany DA - 2001-04-04 PY - 2001 SP - 1(?) AN - OPUS4-1314 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schultze, Karin A1 - Becker, Roland A1 - Win, Tin A1 - Nehls, Irene T1 - Entwicklung, Herstellung und Zertifizierung eines Referenzmaterials zur Bestimmung von "Organochlorpestiziden in Boden" T2 - Tagung "Tag der Chemie" CY - Potsdam, Deutschland DA - 2000-11-08 PY - 2000 AN - OPUS4-1001 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharkoi, O. A1 - Esslinger, Susanne A1 - Becker, Roland A1 - Weber, M. A1 - Nehls, Irene T1 - Phase I oxidation of alpha- and gamma-hexabromocyclododecane by cytochrome P450 enzymes: simulation of the steroisomerism of hydroxylated metabolites T2 - DIOXIN 2011 CY - Brussels, Belgium DA - 2011-08-21 KW - Bromierte Falmmschutzmittel KW - Hexabromcyclododecan KW - Cytochrom KW - Metaboliten KW - HPLC KW - Simulation PY - 2011 UR - http://www.dioxin20xx.org/pdfs/2011/1810.pdf SN - 1026-4892 VL - 73 SP - 730 EP - 733 AN - OPUS4-27263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharkoi, O. A1 - Becker, Roland A1 - Esslinger, Susanne A1 - Weber, M. A1 - Nehls, Irene T1 - Predicting sites of cytochrome P450-mediated hydroxylation applied to CYP3A4 and hexabromocyclododecane N2 - This article describes a simple and quick in silico method for the prediction of cytochrome P450 (CYP)-mediated hydroxylation of drug-like compounds. Testosterone and progesterone, two known substrates of CYP3A4, are used to test the method. Further, we apply the procedure to predict sites of hydroxylation of isomers of the flame retardant hexabromocyclododecane by CYP3A4. Within the method, the compound is rotated in the binding pocket of the cytochrome, so that each hydrogen under consideration is placed near the active centre. Afterwards, short molecular dynamics simulations are provided for each step of the rotation. All steps of the simulation are compared concerning the distances between the hydrogens and the active centre and the corresponding energies. The computational results correlate well with experimental results. KW - Predicting sites of metabolism KW - Cytochrome P450 KW - Hydroxylation KW - Metabolism of HBCD PY - 2015 U6 - https://doi.org/10.1080/08927022.2014.898845 SN - 0892-7022 SN - 1029-0435 VL - 41 IS - 7 SP - 538 EP - 546 PB - Gordon and Breach CY - New York, NY AN - OPUS4-30492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schallschmidt, Kristin A1 - Becker, Roland A1 - Zwaka, H. A1 - Menzel, R. A1 - Johnen, D. A1 - Fischer-Tenhagen, C. A1 - Rolff, J. A1 - Nehls, Irene T1 - In vitro cultured lung cancer cells are not suitable for animal-based breath biomarker detection N2 - In vitro cultured lung cancer cell lines were investigated regarding the possible identification of volatile organic compounds as potential biomarkers. Gas samples from the headspace of pure culture medium and from the cultures of human lung adenocarcinoma cell lines A549 and Lu7466 were exposed to polypropylene fleece in order to absorb odour components. Sniffer dogs were trained with loaded fleeces of both cell lines, and honey bees were trained with fleeces exposed to A549. Afterwards, their ability to distinguish between cell-free culture medium odour and lung cancer cell odour was tested. Neither bees nor dogs were able to discriminate between odours from the cancer cell cultures and the pure culture medium. Solid phase micro extraction followed by gas chromatography with mass selective detection produced profiles of volatiles from the headspace offered to the animals. The profiles from the cell lines were largely similar; distinct differences were based on the decrease of volatile culture medium components due to the cells' metabolic activity. In summary, cultured lung cancer cell lines do not produce any biomarkers recognizable by animals or gas chromatographic analysis. KW - A549 KW - Honey bees KW - Odour discrimination task KW - Sniffer dogs KW - Solid phase microextraction KW - Volatile organic compounds KW - Volatilome PY - 2015 U6 - https://doi.org/10.1088/1752-7155/9/2/027103 SN - 1752-7155 SN - 1752-7163 VL - 9 IS - 2 SP - 027103-1 EP - 027103-10 PB - IOP CY - Bristol AN - OPUS4-34161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schallschmidt, Kristin A1 - Becker, Roland A1 - Jung, Christian A1 - Bremser, Wolfram A1 - Nehls, Irene A1 - Leschber, G. A1 - Frese, S. A1 - Walles, T. A1 - Neudecker, J. T1 - Comparison of volatile organic compounds from lung cancer patients and healthy controls—challenges and limitations of an observational study N2 - The design and operation of an observational study on the profiles of volatile organic compounds (VOC) in the breath of 37 lung cancer patients and 23 healthy controls of similar age is outlined. The necessity to quantify each VOC considered as potential disease marker on basis of individual calibration is elaborated and the quality control measures required to maintain reproducibility in breath sampling and subsequent instrumental trace VOC analysis using SPME-GC-MS over a study period of 14 months are described. 24 VOC were quantified on basis of their previously suggested potential as cancer markers. The breath concentration levels of aromatic compounds was expectedly increased in smokers while lung cancer patients displayed significantly increased levels of oxygenated VOC such as aldehydes, 2-butanone and 1-butanol. Though sets of selected oxygenated VOC displayed sensitivities and specificities between 80 and 90% using linear discriminant analysis with leave-one-out cross validation the effective selectivity of the breath VOC approach with regard to cancer detection is clearly limited. Results were discussed against the background of the literature on volatile cancer marker investigations and the prospects to link increased VOC levels in patients’ breath with approaches to employ sniffer dogs. Experiences from this study and the literature suggest that the current state of breath VOC based discrimination between cancer patients and healthy controls is hardly improvable. Observational studies tend to observe significant differences mostly in levels of certain oxygenated VOC but without resolution required for practical application. Any step towards practicable exploitation of VOC profile differences for illness detection would have to solve current restrictions set by the low and variable VOC concentrations. Further challenges are the technical complexity of studies involving breath sampling and possibly the limited capability of current analytical procedures to detect instable marker candidates. KW - Breath KW - Volatile organic compounds KW - Marker KW - Cancer KW - Gas chromatography KW - Solid phase microextraction KW - Volatilome PY - 2016 U6 - https://doi.org/10.1088/1752-7155/10/4/046007 SN - 1752-7155 SN - 1752-7163 VL - 10 IS - 4 SP - Article 046007, 1 EP - 17 PB - IOP Publishing AN - OPUS4-37801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nehls, Irene A1 - Wachholz, Sigrid A1 - Lehnik-Habrink, Petra A1 - Becker, Roland A1 - Win, Tin T1 - Neue Referenzmaterialien für die organische Analytik als Instrumente der Qualitätssicherung T2 - Tagung "Tag der Chemie" CY - Potsdam, Deutschland DA - 2000-11-08 PY - 2000 AN - OPUS4-1000 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -