TY - JOUR A1 - Esslinger, Susanne A1 - Becker, Roland A1 - Müller-Belecke, A. A1 - Bremser, Wolfram A1 - Jung, Christian A1 - Nehls, Irene T1 - HBCD stereoisomer pattern in mirror carps following dietary exposure to pure Gamma-HBCD enantiomers KW - Enantiomer-specific determination KW - HPLC-MS/MS KW - Brominated flame retardant KW - Fish feeding experiment KW - Enantiomer fraction KW - Bioisomerization PY - 2010 DO - https://doi.org/10.1021/jf101469q SN - 0021-8561 SN - 1520-5118 VL - 58 IS - 17 SP - 9705 EP - 9710 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-23173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dorgerloh, Ute A1 - Theissen, H. A1 - Becker, Roland A1 - Hilbert, S. A1 - Nehls, Irene T1 - Probennahme und Quantifizierung von LHKW, Ethen und Methan in Grundwasser N2 - Der Einsatz aktiver (Pumpprobennahme, Schöpfprobennahme) und passiver (Diffusionsprobennahme) Probennahmetechniken zur Gehaltsbestimmung von LHKW sowie Ethen und Methan in Grundwasser wird aus ordnungsbehördlicher Sicht hinsichtlich der Vergleichbarkeit von Analysendaten untersucht. Am Beispiel einer Kontamination mit Trichlorethen sowie 1,2-Dichlorethen und Vinylchlorid kann deutlich gemacht werden, dass die Einsatzmöglichkeit der passiven Probennahme durch unzureichende Strömungsverhältnisse im Aquifer sowie biologische Aktivität im Pegelrohr begrenzt ist. Der aktiven Probennahme ist bei ungeklärten oder unzureichenden Strömungsverhältnissen im Grundwasserleiter daher der Vorzug zu geben. Das gaschromatographische Verfahren für Vinylchlorid mittels Dampfraumtechnik wird um die Quantifizierung von Methan und Ethen erweitert. Dabei werden für die Bewertung von Altlasten relevante Bestimmungsgrenzen von 0,1 µg/l (Vinylchlorid, Ethen) sowie 5 µg/l (Methan) erreicht. Aus der Validierung der Analysenmethode und den Ergebnissen verschiedener Probennahmen werden Toleranzbereiche für die Ergebnisse eines Grundwassermonitorings abgeschätzt. Diese Streubreiten von Monitoring- Ergebnissen sollten von Ingenieurbüros und zuständigen Ordnungsbehörden bei der Bewertung der komplexen Abbauprozesse eines LHKW-Grundwasserschadens beachtet werden. KW - Passive sampling KW - Active sampling KW - Groundwater KW - Trichloroethene KW - Vinyl chloride KW - Methane PY - 2010 DO - https://doi.org/10.1007/s00767-010-0144-7 SN - 1430-483X VL - 15 IS - 4 SP - 231 EP - 239 PB - Springer CY - Berlin ; Heidelberg AN - OPUS4-22617 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dorgerloh, Ute A1 - Becker, Roland A1 - Theißen, H. A1 - Nehls, Irene T1 - The quantification of hydrogen and methane in contaminated groundwater: validation of robust procedures for sampling and quantification N2 - A number of currently recommended sampling techniques for the determination of hydrogen in contaminated groundwater were compared regarding the practical proficiency in field campaigns. Key characteristics of appropriate sampling procedures are reproducibility of results, robustness against varying field conditions such as hydrostatic pressure, aquifer flow, and biological activity. Laboratory set-ups were used to investigate the most promising techniques. Bubble stripping with gas sampling bulbs yielded reproducible recovery of hydrogen and methane which could be verified for groundwater sampled in two field campaigns. The methane content of the groundwater was confirmed by analysis of directly pumped samples thus supporting the trueness of the stripping results. Laboratory set-ups and field campaigns revealed that bubble stripping of hydrogen may be restricted to the type of used pump. Concentrations of dissolved hydrogen after bubble stripping with an electrically driven submersible pump were about one order of magnitude higher than those obtained from diffusion sampling. The gas chromatographic determination for hydrogen and methane requires manual injection of gas samples and detection by a pulsed discharge detector (PDD) and allows limits of quantification of 3 nM dissolved hydrogen and 1 µg L-1 dissolved methane in groundwater. The combined standard uncertainty of the bubble stripping and GC/PDD quantification of hydrogen in field samples was 7% at 7.8 nM and 18% for 78 nM. PY - 2010 DO - https://doi.org/10.1039/c0em00091d SN - 1464-0325 SN - 1464-0333 VL - 12 IS - 10 SP - 1876 EP - 1884 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-22176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Becker, Roland A1 - Esslinger, Susanne A1 - Nehls, Irene T1 - Enantiomer-specific analysis of hexabromocyclododecane in fish from Etnefjorden (Norway) N2 - High-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) was applied to sterospecifically quantify the content of α-, β-, and γ-hexabromocyclododecane (HBCD) in six fish species from the Norwegian Etnefjorden. A combination of a β-PM cyclodextrin and an achiral column enabled the paired chromatographic separation of the stereoisomers in the order (-)-α-, (+)-α-, (-)-β-, (+)-β-, (+)-γ- and, (-)-γ-HBCD. The limits of detection were in the range of 6–21 pg g-1 depending on the stereoisomer and the concentrations of α-, β-, and γ-HBCD in fillets ranged from <5.4 ng g-1 to 11.1 µg g-1 lipid weight. α-HBCD enantiomers were throughout dominating, and in most cases the accumulation of the respective first eluted enantiomers ((-)-α-, (-)-β- and (+)-γ-HBCD) was observed. Deviations from the racemic EF-value were considered to be significant if it was outside of the expanded uncertainty range for each of the racemic HBCD-ratios. The composition of HBCD isomers varied between the investigated fish species and the relative high values for the γ-HBCD concentrations for the bottom-dwellers flounder and thorny skate seems to echo the HBCD pattern of ocean sediments. KW - Flame retardant KW - Diastereomers KW - Chiral separation KW - Bioaccumulation KW - Enantiomeric fraction PY - 2010 DO - https://doi.org/10.1016/j.chemosphere.2010.06.019 SN - 0045-6535 SN - 0366-7111 VL - 80 IS - 10 SP - 1241 EP - 1245 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-22377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Esslinger, Susanne A1 - Becker, Roland A1 - Maul, Ronald A1 - Nehls, Irene T1 - Hexabromocyclododecane enantiomers: microsomal degradation and patterns of hydroxylated metabolites N2 - The degradation of the enantiomers of α-, β-, and γ-hexabromocyclododecane (HBCD) by phase I metabolism was investigated using induced rat liver microsomes. HBCD isomers were quantified using HPLC-MS/MS (ESI-) after separation on a combination of a reversed phase and a chiral analytical column. The degradation of all six isomers followed first-order kinetics and the estimated half-lives ranged from 6.3 min for both β-HBCD enantiomers to 32.3 min in case of (+)-γ-HBCD. (+)-α- and (–)-γ-HBCD displayed significantly shorter half-lives than their corresponding antipodes. It could be shown that this degradation led to a significant enrichment of the first eluting enantiomers (–)-α- and (+)-γ-HBCD. Individual patterns of mono- and dihydroxylated derivatives obtained from each α- and γ-HBCD enantiomer were seen to be distinctly characteristic. The patterns of monohydroxylated HBCD derivatives detected in liver and muscle tissues of pollack, mackerel and in herring gull eggs were largely similar to those observed in the in vitro experiments with rat liver microsomes. This enabled individual hydroxy-HBCDs to be assigned to their respective parent HBCD enantiomers. KW - Brominated flame retardant KW - Cytochromes KW - Phase I metabolism KW - Hydroxylation KW - HPLC-MS/MS PY - 2011 DO - https://doi.org/10.1021/es1039584 SN - 0013-936X SN - 1520-5851 VL - 45 IS - 9 SP - 3938 EP - 3944 PB - ACS Publ. CY - Washington, DC AN - OPUS4-23837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Esslinger, Susanne A1 - Becker, Roland A1 - Jung, Christian A1 - Schröter-Kermani, C. A1 - Bremser, Wolfram A1 - Nehls, Irene T1 - Temporal trend (1988-2008) of hexabromocyclododecane enantiomers in herring gull eggs from the german coastal region N2 - Levels of α-, β-, and γ-hexabromocyclododecane (HBCD) were determined in pooled eggs from herring gulls (Larus argentatus) sampled on three bird sanctuaries near the German North Sea coast between 1988 and 2008 (Mellum and Trischen) and the German Baltic Sea coast between 1998 and 2008 (Heuwiese) and archived by the German Environmental Specimen Bank. Pressurized fluid extraction, gel permeation chromatography, and LC–MS/MS using 13C12-labelled isotope standards and a chiral column were applied. α-HBCD was the dominating diastereomer and ranged between 3.7 and 107 ng g-1 lw while β- and γ-HBCD were throughout close to LOQ. The highest α-HBCD concentration was found in eggs from Mellum sampled in the year 2000. Interestingly, HBCD in eggs from the three islands displayed similar time courses with levels increasing to a peak contamination around 2000 and decreasing levels ever since. Chiral signatures of α-HBCD in eggs differed among the islands but indicated a preferential enrichment of the first eluting enantiomer (-)-α-HBCD. KW - Brominated flame retardant KW - Chiral separation KW - HPLC-ESI-MS/MS KW - Enantiomer-specific bioaccumulation PY - 2011 DO - https://doi.org/10.1016/j.chemosphere.2010.12.047 SN - 0045-6535 SN - 0366-7111 VL - 83 IS - 2 SP - 161 EP - 167 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-23351 LA - eng 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 - Dorgerloh, Ute A1 - Becker, Roland A1 - Lutz, A. A1 - Bremser, Wolfram A1 - Hilbert, S. A1 - Nehls, Irene T1 - How to improve reliability in groundwater analysis: over a decade of experience with external quality control in field campaigns on volatile halogenated compounds N2 - The reliability in measurement results obtained during environmental monitoring is crucial for the assessment and further planning of remediation efforts on the respective contaminated sites by the responsible authorities. A case study concerned with groundwater contaminated with perchloroethylene, trichloroethylene and 1,1,2-trichlorotrifluoroethane including their degradation products which involves private contract laboratories and an independent provider of quality assurance (QA) is presented. The experience gained with biannual monitoring campaigns over 14 years indicates that the selection of contractors on basis of accreditation status and successful performance in interlaboratory comparisons are not sufficient. Rather the auditing of the contractors by the QA provider prior to each campaign and the crosschecking of selected monitoring samples by the QA provider led to a lasting improvement of reliability in the contractors' measurement results. A mean deviation of 20% from the reference value determined by the QA provider for the crosschecked samples was reached. KW - Groundwater monitoring KW - External quality management KW - QM KW - VOC PY - 2012 DO - https://doi.org/10.1039/c1em10460h SN - 1464-0325 SN - 1464-0333 VL - 14 IS - 1 SP - 217 EP - 223 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-25288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Gebert, Antje A1 - Emmerling, Franziska A1 - Becker, Roland A1 - Nehls, Irene T1 - Koenigs-Knorr reaction of fusel alcohols with methyl (1-bromo-2,3,4-tri-O-acetyl-alpha-D-glucopyranosid)uronate leading to the protected alkyl glucuronides-crystal structures and high resolution 1H and 13C NMR data N2 - Crystal structures and high resolution 1H and 13C NMR spectral data for methyl (alkyl 2,3,4-tri-O-acetyl-β-D-glucopyranosid)uronates (alkyl = methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl, n-pentyl, 2-methyl-1-butyl and 3-methyl-1-butyl) are presented. KW - D-Glucuronic acid derivates KW - X-ray analysis KW - High resolution NMR KW - Anomeric configuration KW - Synthesis PY - 2012 DO - https://doi.org/10.1016/j.carres.2012.01.002 SN - 0008-6215 SN - 1873-426X VL - 352 SP - 186 EP - 190 PB - Elsevier CY - Amsterdam AN - OPUS4-25759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Becker, Roland A1 - Nehls, Irene T1 - Quantification of ethyl glucuronide in hair: effect of milling on extraction efficiency N2 - Aim: The objective of the study was to provide conclusive evidence for the effect of particle size reduction as by milling on the extractable content of ethyl glucuronide (EtG) of hair samples. Methods: A number of real case hair samples and two pooled hair materials with EtG contents in the range of 10–30 pg/mg were systematically compared with regard to the extraction yield of EtG after cutting to 2–3 mm length and pulverization with a ball mill. After the respective treatment the samples were submitted to aqueous extraction followed by quantification of EtG using HPLC-MS/MS. Results: It was unequivocally demonstrated that milling of hair samples prior to aqueous extraction significantly increases the extractable EtG content compared with cut hair. The effect ranged between 137 and 230% and was seen to occur regardless of the extent of pulverization. Cooling of samples was not necessary to prevent partial degradation of EtG during the grinding procedure. Conclusion: The options currently employed at choice in analytical practice (cutting or milling) were seen to significantly affect the extractable amount of EtG in hair. This is suspected to influence the degree of equivalence of quantification results obtained in different laboratories as well as their respective classification of a test subject's drinking behaviour on the basis of currently recommended cut-off values. PY - 2013 DO - https://doi.org/10.1093/alcalc/agt059 SN - 0735-0414 SN - 0309-1635 SN - 1464-3502 VL - 48 IS - 5 SP - 558 EP - 563 PB - Univ. Press CY - Oxford AN - OPUS4-28843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -