TY - JOUR A1 - Scholz, Philipp A1 - Wachtendorf, Volker A1 - Elert, Anna Maria A1 - Falkenhagen, Jana A1 - Becker, Roland A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Tschiche, Harald A1 - Reinsch, Stefan A1 - Weidner, Steffen ED - Scholz, Philipp T1 - Analytical toolset to characterize polyurethanes after exposure to artificial weathering under systematically varied moisture conditions JF - Polymer Testing N2 - Polyether and -ester urethanes (PU) were exposed to artificial weathering at 40 °C and artificial UV radiation in a weathering chamber. In 3 parallel exposures, humidity was varied between dry, humid, and wet conditions. Material alteration was investigated by various analytical techniques like size exclusion chromatography (SEC), liquid chromatography-infrared spectroscopy (LC-FTIR), thermal-desorption gas chromatography-mass spectrometry (TD-GC-MS), fluorescence mapping and dynamic mechanical analysis (DMA). Our results show that depending on the weathering conditions, different degradation effects can be observed. By means of SEC an initial strong decrease of the molar masses and a broadening of the mass distributions was found. After a material dependent time span this was followed by a plateau where molar mass changes were less significant. A minor moisture-dependent degradation effect was only found for polyester PU. Fluorescence measurements on two materials revealed an increase in the luminescence intensity upon weathering process reaching a saturation level after about 500 h. The changes in the optical properties observed after different exposure conditions and times were very similar. The TD-GC-MS data showed the fate of the stabilizers and antioxidant in the course of weathering. LC-FTIR measurements revealed a change in peak intensities and the ratio of urethane and carbonyl bands. KW - Polyurethane KW - Artificial weathering KW - Moisture KW - Crosslinking KW - Degradation PY - 2019 UR - https://www.sciencedirect.com/science/article/pii/S0142941819303708 DO - https://doi.org/10.1016/j.polymertesting.2019.105996 SN - 0142-9418 VL - 78 SP - 105996, 1 EP - 9 PB - Elsevier CY - Amsterdam AN - OPUS4-48625 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 JF - Environmental science & technology 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 - 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 JF - Journal of Breath Research 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 DO - 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 - 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 JF - Journal of agricultural and food chemistry 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 - Reck, Günter A1 - Becker, Roland T1 - Bis­[N-n-butyl-N-(3,5-di-tert-butyl-2-hydroxy­benzyl)­di­thio­carbamato-Kappa²S,S']zinc(II) JF - Acta crystallographica E N2 - Both zinc di­thio­carbamates and sterically hindered phenols are known to exhibit antioxidant activity. As part of an investigation on the effect of both moieties being combined in one mol­ecule, the title compound, [Zn(C17H26NOS2)2], has been prepared and its crystal structure determined. PY - 2003 DO - https://doi.org/10.1107/S1600536803007372 SN - 1600-5368 VL - 59 IS - 5 SP - m234 EP - m235 PB - Munksgaard CY - Copenhagen AN - OPUS4-2464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Koch, Matthias A1 - Wachholz, Sigrid A1 - Win, Tin T1 - Quantification of total petrol hydrocarbons (TPH) in soil by IR-spectrometry and gas chromatography - conclusions from three proficiency testing rounds JF - Accreditation and quality assurance N2 - Due to the utilisation of 1,1,2-trichlorotrifluoroethane (CFE) as extraction solvent the IR-spectrometric determination of total petrol hydrocarbon (TPH) in soil according to ISO/TR 11046 has been replaced by gas chromatography/flame ionisation detection (GC/FID) after extraction with a halogen-free solvent according to ISO/DIS 16703:2001. The results obtained with both methods by field laboratories in three proficiency testing (PT) rounds are compared. The consensus means obtained with GC/FID are typically 10%-20% (ranging between 0% and 25%) higher than those found with IR-spectroscopy. On the contrary, coefficients of variation (CV) are roughly double in case of GC/FID and are briefly discussed against the background of the Horwitz equation. KW - Hydrocarbons KW - Soil KW - IR spectrometry KW - Gas chromatography KW - Interlaboratory comparison PY - 2002 DO - https://doi.org/10.1007/s00769-002-0476-9 SN - 0949-1775 SN - 1432-0517 VL - 7 IS - 7 SP - 286 EP - 289 PB - Springer CY - Berlin AN - OPUS4-1627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Buge, Hans-Gerhard A1 - Win, Tin T1 - Determination of pentachlorphenol (PCP) in waste wood - method comparison by a collaborative trial JF - Chemosphere N2 - Two independently developed and validated procedures for the determination of pentachlorophenol (PCP) in waste wood were compared by means of a collaborative trial. Both methods foresee quantification of PCP by gas chromatography (GC-ECD) after acetylation and differ with regard to the use of methanol or toluene/sulphuric acid, respectively, as solvent in the sonication extraction step. Test samples with established analyte homogeneity were prepared from a ground “real life” starting material. A total of 23 participating laboratories with experience in wood preservative analysis were instructed to apply both methods to three levels of content in the range of 0.5–20 mg PCP/kg. In case of the toluene/sulphuric acid extraction, lower recoveries and higher interlaboratory dispersion of results at the higher PCP contents were observed. Seen against the background of the Horwitz equation a reproducibility standard deviation of not, vert, similar19% for the methanol extraction at the 4.5 mg/kg level meets the requirement for a sound analytical method. Thus, the sonication extraction procedure with methanol has been annexed as a reference method to the German waste wood regulation. KW - Extraction KW - Derivatisation KW - Sonication KW - Analysis KW - Gas chromatography KW - Regulation PY - 2002 DO - https://doi.org/10.1016/S0045-6535(02)00004-8 SN - 0045-6535 SN - 0366-7111 VL - 47 SP - 1001 EP - 1006 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-1628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reck, Günter A1 - Becker, Roland T1 - Phenanthroline complexes of zinc and calcium carbamates JF - Acta crystallographica C N2 - Bis(N,N-di-n-butyl­di­thio­carbamato-?2S,S')(1,10-phenanthroline-?2N,N')­zinc(II) ethanol hemisolvate, [Zn(C9H18NS2)2(C12H8N2)]·0.5C2H6O, (I), and bis(N,N-di-n-hexyldithiocarbamato-?2S,S')­bis(1,10-phenanthroline-?2N,N')calcium(II), [Ca(C13H26NS2)2(C12H8N2)2], (II), are mixed-ligand com­plexes. In the first compound, the Zn atom has a distorted octahedral coordination, while in the second compound, the Ca atom is eight-coordinate, with four S and four N atoms forming a highly distorted cube. KW - X-ray structure analyses KW - Metal-organic complexes KW - Antioxidant properties PY - 2004 DO - https://doi.org/10.1107/S0108270104001441 SN - 0108-2701 SN - 1600-5759 VL - 60 SP - m134 EP - m136 PB - Blackwell Publ. CY - Oxford AN - OPUS4-3110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Nehls, Irene A1 - Dorgerloh, Ute T1 - Interlaboratory comparisons - demonstrating degree of equivalence JF - Accreditation and quality assurance N2 - The role of matrix reference materials in the process of demonstrating the degree of equivalence of measurement results obtained from intercomparisons is outlined, reviewing exemplary selected experience gained at BAM regarding the determination of organic contaminants in environmental matrices. The specific characteristics of reference materials employed in the process of demonstrating equivalence between laboratories in the course of proficiency testing as well as the development, comparison and validation of methods are elaborated. The demand is for series of appropriately characterised samples which are fit for the purpose and it is seen from representative examples that the utilisation of such tailor-made RM designed to tackle the specific need of an analytical problem dominates over certified matrix reference materials in this context. Concluding, the role of certified matrix reference materials in quality assurance is briefly looked at both from the user’s and providers’ points of view. KW - Certification KW - Equivalence KW - Method development KW - Proficiency testing KW - Reference materials PY - 2003 DO - https://doi.org/10.1007/s00769-003-0580-5 SN - 0949-1775 SN - 1432-0517 VL - 8 SP - 150 EP - 155 PB - Springer CY - Berlin AN - OPUS4-2848 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reck, Günter A1 - Becker, Roland T1 - (N,N-Diiso­butyl­di­thio­carbamoyl­sulfinato)­zinc(II) JF - Acta crystallographica E N2 - Zinc di­alkyl di­thio­carbamoyl­sulfinates have been proposed as intermediates in the antioxidant action of the respective zinc di­alkyl di­thio­carbamate additives in hydro­carbon-based plastics and lubricants. As a model compound, zinc diiso­butyl di­thio­carbamoyl­sulfinate, [Zn(C9H18NO2S2)2], has been prepared and its crystal structure determined. PY - 2003 DO - https://doi.org/10.1107/S160053680301314X SN - 1600-5368 VL - 59 IS - 7 SP - m489 EP - m490 PB - Munksgaard CY - Copenhagen AN - OPUS4-2577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Esslinger, Susanne A1 - Becker, Roland A1 - Müller-Belecke, A. A1 - Jung, Christian A1 - Nehls, Irene T1 - Bioisomerization of HBCD: Results of feeding experiments with pure Gamma-HBCD enantiomers T2 - Dioxin 2009 - 29th International symposium on halogenated persistent organic pollutants / Organohalogen compounds (Proceedings) N2 - 1,2,5,6,9,10-hexabromocyclododecane (HBCD), a widely used flame retardant, is an ubiquitous contaminant in the environment. Still, only little is known about the distribution and behavior in the environment such as bioaccumulation or biotransformation of HBCD stereoisomers. In order to investigate enrichment and possible bioisomerization of HBCD stereoisomers, Mirror Carps were exposed to pure (+)- and (-)-γ-HBCD, randomly sampled after a predefined specific period and subjected to enantiomer-specific determination of α-, β-, and γ- HBCD. No evidence for the isomerization of HBCD stereoisomers was observed in Mirror Carp fillets. T2 - Dioxin 2009 - 29th International symposium on halogenated persistent organic pollutants / Organohalogen compounds CY - Beijing, China DA - 2009-08-23 PY - 2009 UR - http://www.dioxin20xx.org/pdfs/2009/09-103.pdf VL - 71 SP - 000487 EP - 000492 CY - Beijing, China AN - OPUS4-21187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Becker, Roland A1 - Jung, Christian A1 - Piechotta, Christian A1 - Nehls, Irene T1 - Investigation of extraction procedures and HPLC-DAD/MS for the determination of the brominated flame retardant tetrabromobisphenol A bis(2,3-dibromopropylether) in environmental samples JF - Analytical and bioanalytical chemistry N2 - A method for the determination of the novel brominated flame retardant tetrabromobisphenol A bis(2,3-dibromopropylether), 1,1'-(isopropylidene)bis[3,5-dibromo-4-(2,3-dibromo-propoxy)-benzene] (TBBPA-dbpe), was developed. Technical TBBPA-dbpe was purified and the results of a thorough physical characterisation are reported. The application of APCI-MS is discussed and the fragmentation patterns are described. Quantification of TBBPA-dbpe was done by HPLC-DAD using external calibration. The validation of the method was accomplished using sediment and sewage sludge samples spiked with defined amounts of authentic TBBPA-dbpe. The average recovery rates of TBBPA-dbpe from spiked samples ranged from 35 to 91% (sediment) and from 57 to 98% (sewage sludge) depending on the respective extraction method. Pressurised fluid extraction (PFE) and fluidised bed extraction were superior to classical Soxhlet and sonication procedures and yielded recovery rates between 90 and 98% with relative standard deviations of 2%. The limits of detection (DTC), identification (ID) and determination (DTM) using HPLC-DAD were 10, 21 and 30 ng g-1 in sediment and 22, 44 and 72 ng g-1 in sewage sludge, respectively. KW - Extraction KW - TBBPA-dbpe KW - Sewage sludge KW - Sediment KW - LC-MS KW - Mass spectrometry KW - APCI KW - HPLC-DAD PY - 2006 DO - https://doi.org/10.1007/s00216-006-0339-z SN - 1618-2642 SN - 1618-2650 VL - 384 IS - 7-8 SP - 1485 EP - 1492 PB - Springer CY - Berlin AN - OPUS4-12255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mueller, Axel A1 - Becker, Roland A1 - Dorgerloh, Ute A1 - Simon, Franz-Georg A1 - Braun, Ulrike T1 - The effect of polymer aging on the uptake of fuel aromatics and ethers by microplastics JF - Environmental Pollution N2 - Microplastics are increasingly entering marine, limnic and terrestrial ecosystems worldwide, where they sorb hydrophobic organic contaminants. Here, the sorption behavior of the fuel-related water contaminants benzene, toluene, ethyl benzene and xylene (BTEX) and four tertiary butyl ethers to virgin and via UV radiation aged polypropylene (PP) and polystyrene (PS) pellets was investigated. Changes in material properties due to aging were recorded using appropriate polymer characterization methods, such as differential scanning calorimetry, Fourier transform infrared spectroscopy, gel permeation chromatography, X-ray photoelectron spectroscopy, and microscopy. Pellets were exposed to water containing BTEX and the ethers at 130-190 mg/L for up to two weeks. Aqueous sorbate concentrations were determined by headspace gas chromatography. Sorption to the polymers was correlated with the sorbate's Kow and was significant for BTEX and marginal for the ethers. Due to substantially lower glass transition temperatures, PP showed higher sorption than PS. Aging had no effect on the sorption behavior of PP. PS sorbed less BTEX after aging due to an oxidized surface layer. KW - BTEX KW - Polypropylene KW - Polystyrene KW - Sorption KW - Degradation PY - 2018 DO - https://doi.org/10.1016/j.envpol.2018.04.127 SN - 0269-7491 VL - 240 SP - 639 EP - 646 PB - Elsevier CY - Amsterdam AN - OPUS4-44990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dorgerloh, Ute A1 - Becker, Roland A1 - Nehls, Irene T1 - Volatile hydrocarbons in contaminated soil: Robustness of fractional quantification using headspace gas chromatography-mass-spectrometry JF - Soil and sediment contamination N2 - Fuel contamination of soils display complex and variable hydrocarbon mixtures with different volatility and toxicity characteristics. A recently suggested headspace procedure for the structure-based quantification of volatile hydrocarbons is evaluated regarding repeatability, reproducibility, and practical robustness. Three aliphatic and three aromatic fractions covering the boiling range between 69 and 216°C were defined as summation parameters by their respective equivalent carbon number ranges. A standard mixture of 35 aliphatic and aromatic hydrocarbons was used for calibration on basis of selected mass fragments specific for the aliphatics and aromatics, respectively. Two standard soils were fortified with the standard mixture or different fuels, respectively, and submitted to the analytical procedure. Limit of detection (LOD) and limit of quantification (LOQ) were for all fractions lower than 0.1 and 0.3 mg/kg, respectively. Analyte recovery was linear up to between 20 and 110 mg hydrocarbons/kg soil depending on the fraction. Hydrocarbon recovery ranged between 80% and 110% depending on the fraction and the repeatability was typically better than 10%. Finally, the impact of extraction solvent variation, column solid-phase polarity, and alternative summation of fractions were investigated. The procedure was applied to liner samples taken from a site contaminated with aviation fuel and its practicability is discussed. KW - Gasoline KW - Contaminated site KW - Equivalent carbon number KW - Fuel KW - Static headspace PY - 2018 DO - https://doi.org/10.1080/15320383.2018.1418287 SN - 1532-0383 SN - 1549-7887 VL - 27 IS - 1 SP - 1 EP - 12 PB - Taylor & Francis AN - OPUS4-43889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sanchez-Martin, Pedro A1 - Becker, Roland A1 - Toepel, J. A1 - Gorbushina, Anna T1 - An improved test for the evaluation of hydrocarbon degradation capacities of diesel-contaminating microorganisms JF - International Biodeterioration & Biodegradation N2 - The development of a test to evaluate the degradation of semi-volatile fuels as diesel by microorganisms is presented. This method is based on the principles described in the CEC-L-103 Standard procedure that is exclusively meant for testing the biodegradability of non-volatile lubricants. Therefore, significant modifications involve aseptic conditions for testing specific microorganisms and conducting the test in closed vessels avoiding evaporation losses, while fuel quantification using gas chromatography-flame ionization detection (GC-FID) is retained. It is suggested that the modified procedure should enable routine application for semi-volatile hydrocarbon-based fuels. GC-FID provides additionally valuable information on the alteration of fuel component patterns during biodegradation. The procedure was successfully tested using two bacteria (Pseudomonas aeruginosa and Sphingomonas sp.) and two yeasts (Moesziomyces sp. and Candida sp.) isolated from real diesel contamination cases. All tested microorganisms caused a significant degradation of diesel fuel achieving hydrocarbon degradation percentages ranging from 23% to 35%. Specific aspects on the test modification and prospects for further modification regarding targeted investigations in the field of fuel contamination by microorganisms are briefly discussed. KW - Biofouling KW - Bacteria KW - Fungi KW - CEC-L-103 KW - GC-FID KW - Reference organisms PY - 2018 DO - https://doi.org/10.1016/j.ibiod.2018.01.009 SN - 0964-8305 VL - 129 SP - 89 EP - 94 PB - Elsevier AN - OPUS4-44524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ricci, M. A1 - Shegunova, P. A1 - Conneely, P. A1 - Becker, Roland A1 - Torres, M. M. A1 - Osuna, M. A. A1 - On, T.P. A1 - Man, L.H. A1 - Baek, S.-Y. A1 - Kim, B. A1 - Hopley, C. A1 - Liscio, C. A1 - Warren, J. A1 - Le Diouron, V. A1 - Lardy-Fontan, S. A1 - Lalere, B. A1 - Mingwu, S. A1 - Kucklick, J. A1 - Vamathevan, V. A1 - Matsuyama, S. A1 - Numata, M. A1 - Brits, M. A1 - Quinn, L. A1 - Fernandes-Whaley, M. A1 - Gören, A.C. A1 - Binici, B. A1 - Konopelko, L. A1 - Krylov, A. A1 - Mikheeva, A. T1 - CCQM-K102: Polybrominated diphenyl ethers in sediment JF - Metrologia N2 - The key comparison CCQM-K102: Polybrominated diphenyl ethers in sediment was coordinated by the JRC, Directorate F - Health, Consumers & Reference Materials, Geel (Belgium) under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM). Thirteen National Metrology institutes or Designated Institutes and the JRC participated. Participants were requested to report the mass fraction (on a dry mass basis) of BDE 47, 99 and 153 in the freshwater sediment study material. The sediment originated from a river in Belgium and contained PBDEs (and other pollutants) at levels commonly found in environmental samples. The comparison was designed to demonstrate participants' capability of analysing non-polar organic molecules in abiotic dried matrices (approximate range of molecular weights: 100 to 800 g/mol, polarity corresponding to pKow < −2, range of mass fraction: 1–1000 μg/kg). All participants (except one using ultrasonic extraction) applied Pressurised Liquid Extraction or Soxhlet, while the instrumental analysis was performed with GC-MS/MS, GC-MS or GC-HRMS. Isotope Dilution Mass Spectrometry approach was used for quantification (except in one case). The assigned Key Comparison Reference Values (KCRVs) were the medians of thirteen results for BDE 47 and eleven results for BDE 99 and 153, respectively. BDE 47 was assigned a KCRV of 15.60 μg/kg with a combined standard uncertainty of 0.41 μg/kg, BDE 99 was assigned a KCRV of 33.69 μg/kg with a combined standard uncertainty of 0.81 μg/kg and BDE 153 was assigned a KCRV of 6.28 μg/kg with a combined standard uncertainty of 0.28 μg/kg. The k-factor for the estimation of the expanded uncertainty of the KCRVs was chosen as k = 2. KW - Intercomparison KW - Traceability KW - Nation metrology institutes PY - 2017 DO - https://doi.org/10.1088/0026-1394/54/1A/08026 SN - 0026-1394 SN - 1681-7575 VL - 54 SP - 08026, 1 EP - 82 AN - OPUS4-41998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer-Tenhagen, C. A1 - Johnen, D. A1 - Nehls, Irene A1 - Becker, Roland T1 - A Proof of Concept: Are Detection Dogs a Useful Tool to Verify Potential Biomarkers for Lung Cancer? JF - Frontiers in Veterinary Science N2 - Early and reliable diagnostic test is essential for effective therapy of lung cancer. Volatile organic compounds that are characteristic for cancer could serve as valuable biomarkers in cancer diagnosis. Both trace analytical and detection dog approaches give some evidence for the existence of such biomarkers. In this proof of concept, study dogs and trace analysis were implemented in combination to gain more information concerning cancer biomarkers. Two dogs were trained to distinguish between absorbed breath samples of lung cancer patients and healthy persons and succeeded with correct identification of patients with 9/9 and 8/9 and correct negative indications from of 8/10 and 4/10 samples from healthy individuals. A recent observational study found that breath samples from lung cancer patients showed an increase in 1-butanol, 2-butanone, 2-pentanone, and hexanal. Synthetic air samples were therefore fortified with these compounds and adsorbed to a fleece. Tested against breath samples from healthy probands, on presentation to the dogs these synthetic samples provoked an indication in three out of four samples. We were able to demonstrate that a combination of the natural nose of a dog and a trace analytic technique can be a valuable concept in the search for cancer biomarkers. KW - Lung cancer KW - Breath KW - Detection dog KW - Biomarkers KW - Sampling KW - Synthetic air PY - 2018 DO - https://doi.org/10.3389/fvets.2018.00052 SN - 2297-1769 VL - 5 SP - Article 52,1 EP - 6 PB - Frontiers Research Foundation CY - Lausanne AN - OPUS4-44466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Altmann, Korinna A1 - Sommerfeld, Thomas A1 - Braun, Ulrike T1 - Quantification of microplastics in a freshwater suspended organic matter using different thermoanalytical methods – outcome of an interlaboratory comparison JF - Journal of Analytical and Applied Pyrolysis N2 - A sedimented freshwater suspended organic matter fortified with particles of polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) was employed in an interlaboratory comparison of thermoanalytical methods for microplastics identification and quantification. Three laboratories performed pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), three others provided results using thermal extraction desorption followed by gas chromatography coupled to mass spectrometry (TED-GC-MS). One participant performed thermogravimetry-infrared spectroscopy (TGA-FTIR) and two participants used thermogravimetry coupled to mass spectrometry (TGA-MS). Further participants used differential scanning microscopy (DSC), a procedure based on micro combustion calorimetry (MCC) and a procedure based on elemental analysis. Each participant employed a different combination of sample treatment, calibration and instrumental Settings for polymer identification and quantification. Though there is obviously room for improvements regarding the between-laboratory reproducibility and the harmonization of procedures it was seen that the participants Performing Py-GC-MS, TED-GC-MS, and TGA-FTIR were able to correctly identify all polymers and to report reasonable quantification results in the investigated concentration range (PE: 20.0 μg/mg, PP: 5.70 μg/mg; PS: 2.20 μg/mg, PET: 18.0 μg/mg). Although for the other methods limitations exists regarding the detection of specific polymers, they showed potential as alternative approaches for polymer quantification in solid environmental matrices. KW - Interlaboratory comparison KW - Microplastics KW - Suspended organic matter KW - Pyrolysis PY - 2020 DO - https://doi.org/10.1016/j.jaap.2020.104829 VL - 148 SP - 1 EP - 6 PB - Elsevier B.V. AN - OPUS4-50977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Sporkert, F. A1 - Lô, I. A1 - Baumgartner, M. T1 - The determination of ethyl glucuronide in hair: Experiences from nine consecutive interlaboratory comparison rounds JF - Forensic Science International N2 - The increasing request for hair ethyl glucuronide (HEtG) in alcohol consumption monitoring according to cut-off levels set by the Society of Hair Testing (SoHT) has triggered a proficiency testing program based on interlaboratory comparisons (ILC). Here, the outcome of nine consecutive ILC rounds organised by the SoHT on the determination of HEtG between 2011 and 2017 is summarised regarding interlaboratory reproducibility and the influence of procedural variants. Test samples prepared from cut hair (1 mm) with authentic (in-vivo incorporated) and soaked (in-vitro incorporated) HEtG concentrations up to 80 pg/mg were provided for 27–35 participating laboratories. Laboratory results were evaluated according to ISO 5725-5 and provided robust averages and relative reproducibility standard deviations typically between 20 and 35% in reasonable accordance with the prediction of the Horwitz model. Evaluation of results regarding the analytical techniques revealed no significant differences between gas and liquid chromatographic methods In contrast, a detailed evaluation of different sample preparations revealed significantly higher average values in case when pulverised hair is tested compared to cut hair. This observation was reinforced over the different ILC rounds and can be attributed to the increased acceptance and routine of hair pulverisation among laboratories. Further, the reproducibility standard deviations among laboratories performing pulverisation were on average in very good agreement with the prediction of the Horwitz model. Use of sonication showed no effect on the HEtG extraction yield. KW - Ethyl glucuronide KW - Interlaboratory comparison KW - Proficiency testing KW - Society of hair testing KW - Reproducibility KW - Pulverization PY - 2018 DO - https://doi.org/10.1016/j.forsciint.2018.04.025 SN - 0379-0738 SN - 1872-6283 VL - 288 SP - 67 EP - 71 PB - Elsevier AN - OPUS4-44881 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Emmerling, Franziska A1 - Becker, Roland T1 - Decabromodiphenylethane JF - Acta crystallographica E N2 - Decabromo­diphenyl­ethane [systematic name: 1,1'-ethane-1,2-diylbis(penta­bromo­benzene)], C14H4Br10 (DBDPE), was crystallized from toluene. The mol­ecule shows crystallographic inversion symmetry. The C—Br distances are in the range 1.873 (7)–1.891 (6) Å; inter­molecular BrBr contacts contribute to the formation of ribbons. KW - Single-crystal X-ray study KW - T = 273 K KW - R factor = 0.043 KW - wR factor = 0.121 KW - Data-to-parameter ratio = 20.4 PY - 2007 DO - https://doi.org/10.1107/S1600536807000219 SN - 1600-5368 VL - 63 IS - 2 SP - o585 EP - o586 PB - Munksgaard CY - Copenhagen AN - OPUS4-14565 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Souza Machado, A. A. A1 - Lau, C. W. A1 - Till, J. A1 - Kloas, W. A1 - Lehmann, A. A1 - Becker, Roland A1 - Rillig, M. C. T1 - Impacts of microplastics on the soil biophysical environment JF - Environmental Science and Technology N2 - Soils are essential components of terrestrial ecosystems that experience strong pollution pressure. Microplastic contamination of soils is being increasingly documented, with potential consequences for soil biodiversity and function. Notwithstanding, data on effects of such contaminants on fundamental properties potentially impacting soil biota are lacking. The present study explores the potential of microplastics to disturb vital relationships between soil and water, as well as its consequences for soil structure and microbial function. During a 5-weeks garden experiment we exposed a loamy sand soil to environmentally relevant nominal concentrations (up to 2%) of four common microplastic types (polyacrylic fibers, polyamide beads, polyester fibers, and polyethylene fragments). Then, we measured bulk density, water holding capacity, hydraulic conductivity, soil aggregation, and microbial activity. Microplastics affected the bulk density, water holding capacity, and the functional relationship between the microbial activity and water stable aggregates. The effects are underestimated if idiosyncrasies of particle type and concentrations are neglected, suggesting that purely qualitative environmental microplastic data might be of limited value for the assessment of effects in soil. If extended to other soils and plastic types, the processes unravelled here suggest that microplastics are relevant long-term anthropogenic stressors and drivers of global change in terrestrial ecosystems. KW - Mikroplastik KW - Einfluß KW - Boden PY - 2018 DO - https://doi.org/10.1021/acs.est.8b02212 SN - 0013-936X SN - 1520-5851 VL - 52 IS - 17 SP - 9656 EP - 9665 PB - American Chemical Society AN - OPUS4-46547 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 JF - Alcohol and alcoholism 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 - 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 JF - Chemosphere 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 - Zeleny, R. A1 - Voorspoels, S. A1 - Ricci, M. A1 - Becker, Roland A1 - Jung, Christian A1 - Bremser, Wolfram A1 - Sittidech, M. A1 - Panyawathanakit, N. A1 - Wong, W. F. A1 - Choi, S.M. A1 - Lo, K.C. A1 - Yeung, W. Y. A1 - Kim, D.H. A1 - Han, J. A1 - Ryu, J. A1 - Mingwu, S. A1 - Chao, W. A1 - Schantz, M.M. A1 - Lippa, K.A. A1 - Matsuyama, S. T1 - Evaluation of the state-of-the-art measurement capabilities for selected PBDEs and decaBB in plastic by the international intercomparison CCQM-P114 JF - Analytical and bioanalytical chemistry N2 - An international intercomparison involving eight national metrology institutes (NMIs) was conducted to establish their current measurement capabilities for determining five selected congeners from the brominated flame retardant classes polybrominated diphenyl ethers and polybrominated biphenyls. A candidate reference material consisting of polypropylene fortified with technical mixtures of penta-, octa- and decabromo diphenyl ether and decabromo biphenyl, which was thoroughly assessed for material homogeneity and stability, was used as study material. The analytical procedures applied by the participants differed with regard to sample pre-treatment, extraction, clean-up, employed calibrants and type of calibration procedure as well as regarding analytical methods used for separation, identification and quantification of the flame retardant congeners (gas chromatography coupled to an electron capture detector (GC-ECD), gas chromatography-mass spectrometry in the electron ionisation mode (GC-EI-MS), gas chromatography-mass spectrometry in the electron capture negative ionisation mode (GC-ECNI-MS), and liquid chromatography-inductive coupled plasma-mass spectrometry (LC-ICP-MS)). The laboratory means agreed well with relative standard deviations of the mean of means of 1.9%, 4.8%, 5.5% and 5.4% for brominated diphenyl ether (BDE) 47, 183 and 209 and for the brominated biphenyl (BB) congener 209, respectively. For BDE 206, a relative standard deviation of 28.5% was obtained. For all five congeners, within-laboratory relative standard deviations of six measurements obtained under intermediate precision conditions were between 1% and 10%, and reported expanded measurements uncertainties typically ranged from 4% to 10% (8% to 14% for BDE 206). Furthermore, the results are in good agreement with those obtained in the characterization exercise for determining certified values for the flame retardant congeners in the same material. The results demonstrate the state-of-the-art measurement capabilities of NMIs for quantifying representative BDE congeners and BB 209 in a polymer. The outcome of this intercomparison (pilot study) in conjunction with possible improvements for employing exclusively calibrants with thoroughly assessed purity suggests that a key comparison aiming at underpinning calibration and measurement capability (CMC) claims of NMIs can be conducted. KW - Flame retardants KW - Polymer KW - Polybrominated diphenyl ethers (PBDEs) KW - Polybrominated biphenyls (PBBs) KW - International intercomparison PY - 2010 DO - https://doi.org/10.1007/s00216-009-3314-7 SN - 1618-2642 SN - 1618-2650 VL - 396 IS - 4 SP - 1501 EP - 1511 PB - Springer CY - Berlin AN - OPUS4-22905 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 JF - Journal of breath research 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 DO - 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 - Durmaz, V. A1 - Weber, M. A1 - Becker, Roland T1 - How to simulate affinities for host-guest systems lacking binding mode information: application to the liquid chromatographic separation of hexabromocyclododecane stereoisomers JF - Journal of molecular modeling N2 - A novel approach for the simulation of host.guest systems by systematically scanning the host moleculefs orientations within the guest cavity is presented along with a thermodynamic strategy for determining preferential binding modes and corresponding optimal interaction energies between host and guest molecules. By way of example, the elution order of hexabromocyclododecane stereoisomers from high performance liquid chromatography separation on a permethylated β-cyclcodextrin stationary phase has been computed using classical molecular dynamics simulations with the explicit solvents water and acetonitrile. Comparison of estimated with experimental separation data reveals remarkable squared coefficients of correlation with R2=0.87 and a very high correlation RLOO2 . 0:72 using the leaveone-out cross-validation method and water as solvent. In particular, the approach presented shapes up as very robust in terms of the evaluated time range under consideration, reflecting well thermodynamic equilibria. These and further observations correlating with experimental results suggest the suitability of the underlying force fields and our multi-mode approach for the estimation of relative binding affinities for host–guest systems with unknown binding modes. KW - Molecular simulation KW - Molecular dynamics KW - Binding affinity KW - Elution order KW - Beta-cyclodextrin PY - 2012 DO - https://doi.org/10.1007/s00894-011-1239-5 SN - 1610-2940 SN - 0948-5023 VL - 18 IS - 6 SP - 2399 EP - 2408 PB - Springer CY - Berlin; Heidelberg AN - OPUS4-26112 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Scholz, Philipp A1 - Jung, Christian A1 - Weidner, Steffen T1 - Thermo-Desorption Gas Chromatography-Mass Spectrometry for investigating the thermal degradation of polyurethanes JF - Analytical Methods N2 - Thermo-Desorption Gas Chromatography-Mass Spectrometry (TD-GC-MS) was used to investigate the thermal degradation of two different polyurethanes (PU). PU samples were heated at different heating rates and the desorbed products were collected in a cold injection system and thereafter submitted to GC-MS. Prospects and limitations of the detection and quantification of semi-volatile degradation products were investigated. A temperature dependent PU depolymerization was found at temperatures above 200 °C proved by an increasing release of 1,4-butanediol and methylene diphenyl diisocyanate (MDI) representing the main building blocks of both polymers. Their release was monitored quantitatively based on external calibration with authentic compounds. Size Exclusion Chromatography (SEC) of the residues obtained after thermodesorption confirmed the initial competitive degradation mechanism indicating an equilibrium of crosslinking and depolymerization as previously suggested. Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry of SEC fractions of thermally degraded PUs provided additional hints on degradation mechanism. KW - Thermo-desorption KW - Mass spectrometry KW - Polyurethanes KW - Thermal degradation PY - 2023 DO - https://doi.org/10.1039/D3AY00173C SN - 1759-9660 SP - 1 EP - 6 PB - Royal Society for Chemistry AN - OPUS4-57307 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 JF - Organohalogen compounds 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 - Groschke, Matthias A1 - Becker, Roland T1 - Comparison of carrier gases for the separation and quantification of mineral oil hydrocarbon (MOH) fractions using online coupled high performance liquid chromatography-gas chromatography-flame ionisation detection JF - Journal of chromatography A N2 - On-line coupled high performance liquid chromatography-gas chromatography-flame ionisation detection (HPLC-GC-FID) was used to compare the effect of hydrogen, helium and nitrogen as carrier gases on the chromatographic characteristics for the quantification of mineral oil hydrocarbon (MOH) traces in food related matrices. After optimisation of chromatographic parameters nitrogen carrier gas exhibited characteristics equivalent to hydrogen and helium regarding requirements set by current guidelines and standardisation such as linear range, quantification limit and carry over. Though nitrogen expectedly led to greater peak widths, all required separations of standard compounds were sufficient and humps of saturated mineral oil hydrocarbons (MOSH) and aromatic mineral oil hydrocarbons (MOAH) were appropriate to enable quantitation similar to situations where hydrogen or helium had been used. Slightly increased peak widths of individual hump components did not affect shapes and widths of the MOSH and MOAH humps were not significantly affected by the use of nitrogen as carrier gas. Notably, nitrogen carrier gas led to less solvent peak tailing and smaller baseline offset. Overall, nitrogen may be regarded as viable alternative to hydrogen or helium and may even extend the range of quantifiable compounds to highly volatile hydrocarbon eluting directly after the solvent peak. KW - Mineral oil hydrocarobons KW - Food KW - Liquid chromatography KW - Gas chromatography KW - MOSH/MOAH PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601450 DO - https://doi.org/10.1016/j.chroma.2024.464946 SN - 0021-9673 VL - 1726 SP - 1 EP - 7 PB - Elsevier CY - New York, NY AN - OPUS4-60145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nehls, Irene A1 - Hanebeck, Olaf A1 - Becker, Roland A1 - Emmerling, Franziska T1 - N-(beta-carboxyethyl)-alpha-isoleucine JF - Acta crystallographica E N2 - The title compound, {2-[(2-carbamoylethyl)amino]-3-methylpentanoic acid}, C9H18N2O3, is of interest with respect to its biological activity. It was formed during an addition reaction between acrylamide and the amino acid isoleucine. The crystal structure is a three-dimensional network built up by intermolecular N–H···O and O–H···N hydrogen bonds. KW - Acrylamid KW - Isoleucin KW - Derivatisierung PY - 2013 DO - https://doi.org/10.1107/S160053681205146X SN - 1600-5368 VL - 69 IS - Part 2 SP - o172-o173, sup-1 - sup-7 PB - Munksgaard CY - Copenhagen AN - OPUS4-27573 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schallschmidt, Kristin A1 - Becker, Roland A1 - Jung, Christian A1 - Rolff, J. A1 - Fichtner, I. T1 - Investigation of cell culture volatilomes using solid phase micro extraction: options and pitfalls exemplified with adenocarcinoma cell lines JF - Journal of chromatography B N2 - Three strategies to sample volatile organic compounds (VOC) from lung cancer cell lines cultured in vitro were compared. Headspace solid phase microextraction was applied in situ to culture flasks and alternatively to subsamples of headspace gas or to nutrient solution subsamples followed by gas chromatography–mass spectrometry. The direct quantification of 55 VOC in the headspace of cell cultures was validated and is discussed with respect to reproducibility and system-related interferences. The role of the VOC background from culture media and usually employed polystyrene culture vessels is examined and was seen to invoke potentially misleading conclusions. The commercial A549 and two further adenocarcinoma cell lines displayed largely similar VOC profiles with distinct differences regarding certain individual substances. There is evidence for the inappropriateness of the standard cell culturing methods in the search for volatile cancer markers. KW - A549 KW - Lung cancer cell culture KW - GC–MS KW - SPME KW - VOC KW - Volatilome KW - Alcohol marker KW - Micropulverization KW - HPLC-MS/MS KW - Fortification KW - Long term stability PY - 2015 DO - https://doi.org/10.1016/j.jchromb.2015.10.004 SN - 0378-4347 SN - 1570-0232 SN - 1387-2273 SN - 1873-376X VL - 1006 SP - 158 EP - 166 PB - Elsevier B.V. CY - Amsterdam [u.a.] AN - OPUS4-34991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Becker, Roland A1 - Jung, Christian A1 - Nehls, Irene T1 - The homogeneity testing of EtG in hair reference materials: A high-throughput procedure using GC-NCI-MS JF - Forensic science international N2 - The validation of a robust quantification procedure for EtG in hair using GC–NCI–MS is presented. Aqueous extraction is followed by complete lyophylization of the extract and derivatization with pentafluoropropionic anhydride (PFPA) under controlled temperature and duration. Clean-up of extracts was dispensable and standard single quadrupole MS displayed sufficient selectivity and sensitivity. The method displayed a wide linearity range and enabled LOD of 0.68 pg/mg, LOQ of 2.4 pg/mg, and precision below 8.12%. Since EtG was seen to display prolonged stability in the aqueous extracts and after derivatization with PFPA this straightforward procedure allows a routine throughput of large quantities of samples with little proneness to procedural scatter of results. The method was applied to demonstrate the homogeneity of two hair reference materials with mean EtG contents of 8.48 pg/mg and 22.0 pg/mg. Aside from the application in homogeneity studies of hair reference materials predominantly in the concentration range of 10–50 pg/mg the method was also designed for daily routine quantification of real-world sample with regard to drinking behavior assessment. KW - Extraction KW - Derivatization KW - High-throughput analysis KW - Reference materials KW - Homogeneity KW - Measurement uncertainty PY - 2013 DO - https://doi.org/10.1016/j.forsciint.2013.01.018 SN - 0379-0738 SN - 1872-6283 VL - 226 IS - 1-3 SP - 202 EP - 207 PB - Elsevier Ltd. CY - Amsterdam [u.a.] AN - OPUS4-27998 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ammann, Dominic A1 - Becker, Roland A1 - Kohl, Anka A1 - Hänisch, Jessica A1 - Nehls, Irene T1 - Degradation of the ethyl glucuronide content in hair by hydrogen peroxide and a non-destructive assay for oxidative hair treatment using infra-red spectroscopy JF - Forensic science international N2 - The assessment of quantification results of the alcohol abuse marker ethyl glucuronide (EtG) in hair in comparison to the cut-off values for the drinking behavior may be complicated by cosmetic hair bleaching. Thus, the impact of increasing exposure to hydrogen peroxide on the EtG content of hair was investigated. Simultaneously, the change of absorbance in the range of 1000–1100 cm-1 indicative for the oxidation of cystine was investigated non-destructively by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) using pulverized portions of the respective hair samples. Hair samples treated with hydrogen peroxide consistently displayed a significantly increased absorbance at 1040 cm-1 associated with the formation of cysteic acid. The EtG content decreased significantly if the hair was treated with alkaline hydrogen peroxide as during cosmetic bleaching. It could be shown that ATR-FTIR is capable of detecting an exposure to hydrogen peroxide when still no brightening was visible and already before the EtG content deteriorated significantly. Thus, hair samples suspected of having been exposed to oxidative treatment may be checked non-destructively by a readily available technique. This assay is also possible retrospectively after EtG extraction and using archived samples. KW - Hair testing KW - Oxidation KW - Bleaching KW - Cysteic acid KW - HPLC–MS/MS PY - 2014 DO - https://doi.org/10.1016/j.forsciint.2014.07.029 SN - 0379-0738 SN - 1872-6283 VL - 244 SP - 30 EP - 35 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-31755 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Dorgerloh, Ute A1 - Paulke, E. A1 - Mumme, J. A1 - Nehls, Irene T1 - Hydrothermal carbonization of biomass: Major organic components of the aqueous phase JF - Chemical engineering & technology N2 - Process waters obtained from hydrothermal carbonization (HTC) of wheat straw, a biogas digestate derived thereof, and four woody biomass feedstocks were quantified regarding the total organic carbon (TOC) and selected organic compounds. HTC runs revealed that TOC loads were largely unaffected by process severity or type of feedstock whereas the C2–C6 fatty acids, determined by GC, displayed clear effects of temperature and feedstock. HPLC demonstrated simultaneously the initial increase and subsequent consumption of cellulose-derived furfural and 5-hydroxymethylfurfural as well as the increase of the lignin-derived 2-methoxyphenol. 2-Methylbenzofuran, an example for a substance potentially harmful to aquatic biota, was observed in high concentration in the HTC liquor from wheat straw-based feedstocks. KW - Furfurals KW - Gas chromatography KW - Liquid chromatography KW - Phenols KW - Process water KW - Total organic carbon PY - 2014 DO - https://doi.org/10.1002/ceat.201300401 SN - 0930-7516 SN - 1521-4125 VL - 37 IS - 3 SP - 511 EP - 518 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-30333 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Becker, Roland A1 - Nehls, Irene T1 - Determination of ethyl glucuronide in hair: a rapid sample pretreatment involving simultaneous milling and extraction JF - International journal of legal medicine N2 - A combination of simultaneous milling and extraction known as micropulverized extraction was developed for the quantification of the alcohol marker ethyl glucuronide (EtG) in hair samples using a homogeneous reference material and a mixer mill. Best extraction results from 50 mg of hair were obtained with 2-mL plastic tubes containing two steel balls (Ø = 5 mm), 0.5 mL of water and with an oscillating frequency of 30 s-1 over a period of 30 min. EtG was quantified employing a validated GC-MS procedure involving derivatization with pentafluoropropionic acid anhydride. This micropulverization procedure was compared with dry milling followed by separate aqueous extraction and with aqueous extraction after manual cutting to millimeter-size snippets. Micropulverization yielded 28.0±1.70 pg/mg and was seen to be superior to manually cutting (23.0±0.83 pg/mg) and equivalent to dry grinding (27.7±1.71 pg/mg) with regard to completeness of EtG extraction. The option to process up to 20 samples simultaneously makes micropulverization especially valuable for the high throughput of urgent samples. KW - Ethyl glucuronide KW - Hair KW - Micropulverized extraction KW - GC-MS PY - 2014 DO - https://doi.org/10.1007/s00414-013-0939-z SN - 0937-9827 SN - 1437-1596 VL - 128 IS - 1 SP - 69 EP - 72 PB - Springer CY - Berlin ; Heidelberg AN - OPUS4-30063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, M. A1 - Durmaz, V. A1 - Becker, Roland A1 - Esslinger, Susanne T1 - Predictive identification of Pentabromocyclododecene (PBCD) isomers with high binding affinity to hTTR T2 - Dioxin 2009 - 29th International symposium on halogenated persistent organic pollutants / Organohalogen compounds (Proceedings) N2 - The binding affinities of the six main hexabromocyclododecane (HBCD) stereoisomers and all of their possible 48 allylic pentabromocyclododecene (PBCD) metabolites to the endocrinous human transthyretin receptor (hTTR) were investigated and compared to the natural binder thyroxine, and the two brominated diphenyl ethers BDE-47 and 3-hydroxy-BDE-47. The endocrine disrupting potency was approximated by a combination of two methods: a surface matching with the natural binder thyroxine (T4) followed by approximation of free binding energies for various binding modes within hTTR. The results indicate slightly higher binding affinities for both BDE structures than for T4 itself and similarly high affinities for two trans-configurated PBCD isomers. For many other PBCD isomers, intermediate values were computed, whereas all HBCD diastereomers yielded significantly lower binding affinities. T2 - Dioxin 2009 - 29th International symposium on halogenated persistent organic pollutants / Organohalogen compounds CY - Beijing, China DA - 2009-08-23 KW - Flammschutzmittel KW - Thyroxin KW - Molecular modeling PY - 2009 UR - http://www.dioxin20xx.org/pdfs/2009/09-54.pdf VL - 71 SP - 000247 EP - 000252 CY - Beijing, China AN - OPUS4-20980 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Andrea A1 - Wander, Lukas A1 - Becker, Roland A1 - Goedecke, Caroline A1 - Braun, Ulrike T1 - High-throughput NIR spectroscopic (NIRS) detection of microplastics in soil JF - Environmental Science and Pollution Research N2 - The increasing pollution of terrestrial and aquatic ecosystems with plastic debris leads to the accumulation of microscopic plastic particles of still unknown amount. To monitor the degree of contamination analytical methods are urgently needed, which help to quantify microplastics (MP). Currently, time-costly purified materials enriched on filters are investigated both by micro-infrared spectroscopy and/or micro-Raman. Although yielding precise results, these techniques are time consuming, and are restricted to the analysis of a small part of the sample in the order of few micrograms. To overcome these problems, here we tested a macroscopic dimensioned NIR process-spectroscopic method in combination with chemometrics. For calibration, artificial MP/soil mixtures containing defined ratios of polyethylene, polyethylene terephthalate, polypropylene, and polystyrene with diameters < 125 µm were prepared and measured by a process FT-NIR spectrometer equipped with a fiber optic reflection probe. The resulting spectra were processed by chemometric models including support vector machine regression (SVR), and partial least squares discriminant analysis (PLS-DA). Validation of models by MP mixtures, MP-free soils and real-world samples, e.g. and fermenter residue, suggest a reliable detection and a possible classification of MP at levels above 0.5 to 1.0 mass% depending on the polymer. The benefit of the combined NIRS chemometric approach lies in the rapid assessment whether soil contains MP, without any chemical pre-treatment. The method can be used with larger sample volumes and even allows for an online prediction and thus meets the demand of a high-throughput method. KW - Microplastics KW - Soil KW - Chemometrics KW - PLS-DA KW - Support vector machines KW - Near Infrared Spectroscopy PY - 2018 DO - https://doi.org/10.1007/s11356-018-2180-2 SN - 1614-7499 SN - 0944-1344 VL - 26 IS - 8 SP - 7364 EP - 7374 PB - Springer AN - OPUS4-45405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Buge, Hans-Gerhard A1 - Nehls, Irene T1 - The determination of adsorbable organically bound halogens (AOX) in soil: interlaboratory comparisons and reference materials JF - Accreditation and quality assurance N2 - The interlaboratory variability in the quantification of adsorbable organically bound halogens (AOX) in industrially contaminated soil is presented. Three consecutive rounds of a proficiency testing scheme, in which between 88 and 119 routine laboratories participated, yielded relative reproducibility standard deviations between 7 and 20% at AOX contents between 10.9 and 268 mg kg-1. Nineteen laboratories with established proficiency were invited to participate in the certification of the AOX content in three soil reference materials meant for the internal quality control in analytical laboratories. The certified values are (1349 ± 59) mg kg-1, (80 ± 7) mg kg-1 and (102 ± 8) mg kg-1, respectively. KW - Certified reference materials KW - European Reference Material KW - Proficiency testing KW - Organohalogen compounds KW - Summation parameter PY - 2007 DO - https://doi.org/10.1007/s00769-007-0308-z SN - 0949-1775 SN - 1432-0517 VL - 12 IS - 12 SP - 647 EP - 651 PB - Springer CY - Berlin AN - OPUS4-16670 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 JF - Molecular simulation 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 DO - 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 - Becker, Roland A1 - Sauer, Andreas A1 - Bremser, Wolfram T1 - Fifteen years of proficiency testing of total petrol hydrocarbon determination in soil: a story of success JF - Accreditation and Quality Assurance N2 - The total petrol hydrocarbon (TPH) content in soil is determined by gas chromatographic separation and flame ionisation detection according to ISO 16703 in routine laboratories for about 20 years. The development of the interlaboratory variability observed with this analytical procedure over 15 years in a proficiency testing scheme conducted annually with more than 170 participants is evaluated in detail. A significant improvement of the reproducibility standard deviation among participants is observed over the years and attributed to an increasing familiarity with the procedure. Nevertheless, the determination of TPH in the environmentally relevant mass fraction range between 500 mg/kg and 10 000 mg/kg in soils or sediments is far from reaching the reproducibility standard deviations predicted by the Horwitz curve. It is seen that laboratories with sporadic participation tend to report higher bias, while a core group of laboratories participating on a regular basis arrived at reproducibility standard deviations below 20 %. Results from a given laboratory obtained on two different samples tend to be highly correlated in the same PT round indicating a sound repeatability. Expectedly, the within-laboratory correlation between results from consecutive rounds was considerably lower. However, results from consecutive rounds with a temporal distance of 1, 2 or 3 years revealed largely similar correlations which suggests that the within-laboratory reproducibility adjusts to a constant level at least after a period of 1 year. KW - Mineralölkohlenwasserstoffe KW - Boden KW - Ringversuch KW - Gaschromatographie KW - GC-FID KW - Eingnugsprüfung KW - Proficiency Testing PY - 2019 DO - https://doi.org/10.1007/s00769-019-01383-x SN - 0949-1775 SN - 1432-0517 VL - 24 IS - 4 SP - 289 EP - 296 PB - Springer AN - OPUS4-48419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Becker, Roland A1 - Emmerling, Franziska A1 - Jung, Christian A1 - Nehls, Irene T1 - Enantioselective Preparative HPLC Separation of the HBCD-Stereoisomers from the Technical Product and Their Absolute Structure Elucidation Using X-Ray Crystallography JF - Chirality N2 - 1,2,5,6,9,10-Hexabromocyclododecane (HBCD) is a widely used flame retardant, which tends to persist in the environment and accumulates in biota. The six stereoisomers (three racemates named α-, β-, and γ-HBCD) of the technical mixture were isolated with high-performance liquid chromatography (HPLC). Direct separations were performed on a chiral stationary phase containing permethylated -cyclodextrin (NUCLEODEX -PM column) and the pure enantiomers of α-, β-, and γ-HBCD were physically characterized for the first time. The absolute configurations of all six isomers were determined by anomalous dispersion using single crystal X-ray crystallography. Optical rotations αD in tetrahydrofuran were +4.2/-4.0 (α-HBCD), +26.1/-27.5 (β-HBCD), and +68.0/-66.3 (γ-HBCD). The sense of rotation could be correlated with the absolute configurations of α-, β-, and γ-HBCD enantiomers and their order of elution on a chiral permethylated β-cyclodextrin-bonded stationary phase. The diastereomers α-, β-, and γ-HBCD displayed distinctly different melting points as well as 1H-, 13C NMR, and IR spectra. KW - Brominated flame retardant KW - Chiral separation KW - Anomalous dispersion KW - Crystal structures KW - Optical rotation KW - Absolute configuration PY - 2007 DO - https://doi.org/10.1002/chir.20366 SN - 0899-0042 SN - 1520-636X VL - 19 IS - 3 SP - 214 EP - 222 PB - Wiley-Liss CY - New York, NY AN - OPUS4-14718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Emmerling, Franziska A1 - Kraus, Werner A1 - Becker, Roland A1 - Nehls, Irene T1 - n-Propyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside JF - Acta crystallographica E N2 - The title compound [systematic name: (2R,3R,4S,5R,6R) 2-(acetoxymethyl)-6-propoxytetrahydro-2H-pyran-3,4,5-triyl triacetate], C17H26O10, was formed by a Koenigs-Knorr reaction of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide and n-propanol. The central ring adopts a chair conformation. The crystal does not contain any significant interactions such as hydrogen bonds. PY - 2013 DO - https://doi.org/10.1107/S1600536812051495 SN - 1600-5368 VL - 69 IS - Part 2 SP - o158, sup-1 - sup-7 PB - Munksgaard CY - Copenhagen AN - OPUS4-27439 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Dorgerloh, Ute A1 - Sauer, Andreas A1 - Hofmann, Andrea T1 - Quality control in extended measurement campaigns: selection of contract laboratories by proficiency testing exemplified for the trace analysis of anilines in groundwater JF - Accreditation and quality assurance N2 - An interlaboratory comparison for the determination of aniline, nine methylated anilines and chlorinated anilines in contaminated groundwater (each compound between 1 µg L-1 and 750 µg L-1) was conducted as proficiency test for the selection of contract laboratories for a groundwater monitoring campaign. For the 13 participants, two different test sample series were prepared from a stabilized real case groundwater. Series A was the groundwater as sampled in the field and series B was prepared from series A by spiking with selected anilines. Homogeneity and stability investigations revealed that contaminated groundwater provides a viable basis for the preparation of ring test samples for the determination of anilines. Analytical procedures were limited to the standardized liquid–liquid extraction or solid-phase extraction in combination with gas chromatography/mass spectrometry (DIN 38407-16:1999). The robust consensus values were evaluated according to the standardized protocol of DIN 38402-45:2013. Robust reproducibility standard deviations ranged largely between 20?% and 60?% depending on the analyte. The proficiency assessment of individual participants combined the qualitative aspect of correct peak identification with the quantitative determination of individual concentrations within set limits in a unified approach. It could be shown that the accreditation status of laboratory and the existence of a standardized analytical procedure do not substitute a problem-related proficiency assessment of potential contractors. KW - Aniline KW - Chloroanilines KW - Methylanilines KW - Groundwater KW - Interlaboratory comparison KW - Proficiency test PY - 2014 DO - https://doi.org/10.1007/s00769-014-1072-5 SN - 0949-1775 SN - 1432-0517 N1 - Geburtsname von Sauer, Andreas: Buchholz, A. - Birth name of Sauer, Andreas: Buchholz, A. VL - 19 IS - 5 SP - 371 EP - 376 PB - Springer CY - Berlin AN - OPUS4-31756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharf, Holger A1 - Becker, Roland A1 - Bremser, Wolfram A1 - Buge, Hans-Gerhard A1 - Lück, Detlef T1 - Certification of the mass fractions of trace elements and pentachlorophenol in an impregnated wood reference material JF - Accreditation and quality assurance N2 - The resource-saving utilisation of recovered waste wood is a matter of growing concern. In several European countries, this utilisation is governed by regulations and is dependent on the contents of certain trace elements and organic compounds. Thus, for decisionmaking with respect to waste wood management (recycling or combustion), reliable analytical data are needed and, due to their great economic and environmental impact, must be assured by appropriate quality control. To support the improvement in quality assurance in waste wood analysis, for the first time, a wood reference material was certified for its mass fractions of arsenic, cadmium, chromium, copper, lead, mercury, and pentachlorophenol (PCP). These analytes were selected because they represent typical constituents of wood preservatives most widely used in the past. Material preparation and testing of homogeneity and stability were carried out by BAM Federal Institute for Materials Research and Testing. The certification measurements were performed involving selected laboratories with documented expertise in the field of waste wood analysis. The certified values and their corresponding uncertainties were assigned in full compliance with the requirements of ISO Guide 35. The certified mass fractions and their expanded uncertainties (k/i> = 2) are as follows: (3.1 ± 0.5) mg/kg for As, (3.02 ± 0.24) mg/kg for Cd, (36.4 ± 2.6) mg/kg for Cr, (22.9 ± 1.7) mg/kg for Cu, (0.60 ± 0.14) mg/kg for Hg, (39 ± 4) mg/kg for Pb, and (7.9 ± 0.6) mg/kg for PCP. The certified material is available as European Reference Material ERM®-CD100. KW - Waste wood KW - Trace elements KW - Pentachlorophenol KW - Certification KW - European reference material PY - 2010 DO - https://doi.org/10.1007/s00769-010-0699-0 SN - 0949-1775 SN - 1432-0517 VL - 15 IS - 11 SP - 613 EP - 619 PB - Springer CY - Berlin AN - OPUS4-22392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Riddell, N. A1 - Becker, Roland A1 - Chittim, B. A1 - Emmerling, Franziska A1 - Köppen, Robert A1 - Lough, A. A1 - McAlees, A. A1 - McCrindle, R. T1 - Preparation and X-ray structural characterization of further stereoisomers of 1,2,5,6,9,10-hexabromocyclododecane JF - Chemosphere N2 - Technical 1,2,5,6,9,10-hexabromocyclododecane (HBCD) consists largely of three diastereomers (α-, β-, and γ-HBCD) produced by the trans addition of bromine to cis,trans,trans-cyclododeca-1,5,9-triene (CDT). However, another seven diastereomers are theoretically possible and may be produced by trans addition of bromine across the double bonds of the other three isomers of 1,5,9-CDT. There are indications that small amounts of the minor HBCD isomers may be present in commercial HBCD mixtures or in products containing this brominated flame retardant (BFR). Such minor components may indeed derive from traces of other 1,5,9-CDTs in the cis, trans, trans starting material, however their formation may also be possible through isomerizations during the processing of this BFR or by bioisomerization subsequent to its release into the environment. Two of the seven additional diastereomers (δ- and ε-HBCD) were synthesized previously from trans,trans,trans-CDT. We now report the preparation of the remaining five diastereomers, ζ-, η-, and θ-HBCD from cis,cis,trans-CDT and ι- and κ-HBCD from cis,cis,cis-CDT, and their characterization by 1H NMR spectroscopy and X-ray crystallography. The availability of these further diastereomers of HBCD should aid in determining if the minor isomers are present in commercial samples of this BFR, in products containing HBCDs, or in environmental samples. We have also carried out an X-ray crystal structure determination on ε-HBCD, so that crystal structures are now available for all 10 HBCD diastereomers. KW - Brominated flame retardants KW - HBCDs KW - Minor isomers KW - X-ray PY - 2011 DO - https://doi.org/10.1016/j.chemosphere.2011.06.014 SN - 0045-6535 SN - 0366-7111 VL - 84 IS - 7 SP - 900 EP - 907 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-24298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Buge, Hans-Gerhard A1 - Bremser, Wolfram A1 - Nehls, Irene T1 - Mineral oil content in sediments and soils: comparability, traceability and a certified reference material for quality assurance JF - Analytical and bioanalytical chemistry N2 - The performance of twelve laboratories with previously established proficiency in the determination of the mineral oil content in a fresh water sediment is described. The summation parameter total petrol hydrocarbon (TPH) is defined according to ISO 16703:2004 with regard to the sample preparation to be applied, the flame ionisation detection (FID) and the boiling range of C10–C40 to be integrated. Comprehensive tests of homogeneity and stability have been carried out on the candidate material using appropriate models. The outcome of the study served as the basis for the certification of the candidate reference material as ERM-CC015a. The certified mass fraction is 1,820±130mgkg-1 and traceability was established by using an appropriate calibration standard certified for the mass fraction of C10–C40. The interlaboratory scatter of measurement results in this exercise can largely be explained by the variability of the individual calibrations based on this common calibration standard. KW - Total petroleum hydrocarbons KW - Extraction KW - Gas chromatography KW - Calibration KW - Interlaboratory study PY - 2006 DO - https://doi.org/10.1007/s00216-006-0423-4 SN - 1618-2642 SN - 1618-2650 VL - 385 IS - 3 SP - 645 EP - 651 PB - Springer CY - Berlin AN - OPUS4-12399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krysell, M. A1 - Becker, Roland A1 - Wegener, J. W. A1 - Buge, Hans-Gerhard T1 - Certified reference materials for organic contaminants in sewage sludge - a feasibility study JF - Accreditation and quality assurance N2 - As an answer to the re-evaluation of the European sludge directive, two novel reference materials for organic components in municipal sludge have been produced and test certified for AOX (absorbable organic halogens), PAH (polycyclic aromatic hydrocarbons), NPE (nonylphenol and nonylphenolethoxylates), DEHP (di(2-ethylhexyl)phthalate), bisphenol A, and BFR (brominated flame retardants). The materials were prepared from raw sludge without spiking or mixing of different sludges. The study demonstrated that the technique for the preparation of a suitable reference material, sufficiently homogenous and stable, and with concentration levels that answer the needs of the laboratories and the relevant authorities, can now be presented in detail. The results, furthermore, show there is a need for method validation and standardisation of the measurements of NPEs and certain BFR congeners, and that the development of the laboratory structure in Europe, with fewer and more specialised laboratories, might become a major obstacle when trying to find a sufficient number of laboratories being appropriately proficient for this kind of study in the future. KW - Organic pollutants KW - Municipal sludge KW - CRM KW - AOX KW - BPA KW - PAH KW - DEHP KW - NPE KW - BFR PY - 2008 DO - https://doi.org/10.1007/s00769-008-0431-5 SN - 0949-1775 SN - 1432-0517 VL - 13 IS - 10 SP - 553 EP - 562 PB - Springer CY - Berlin AN - OPUS4-18362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weber, M. A1 - Becker, Roland A1 - Durmaz, V. A1 - Köppen, Robert T1 - Classical hybrid Monte-Carlo simulation of the interconversion of hexabromocyclododecane stereoisomers JF - Molecular simulation KW - HBCD KW - Isomerisation KW - Statistical thermodynamics KW - Kinetics PY - 2008 DO - https://doi.org/10.1080/08927020802208968 SN - 0892-7022 SN - 1029-0435 VL - 34 IS - 6-7 SP - 727 EP - 736 PB - Gordon and Breach CY - New York, NY AN - OPUS4-18261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mönch, Bettina A1 - Emmerling, Franziska A1 - Kraus, Werner A1 - Becker, Roland A1 - Nehls, Irene T1 - Isopropyl 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranoside JF - Acta crystallographica E N2 - The title compound, C17H26O10, was formed by a Koenigs-Knorr reaction of 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide and propan-2-ol. The central ring adopts a chair conformation. The crystal does not contain any significant intermolecular interactions. PY - 2013 DO - https://doi.org/10.1107/S1600536812051483 SN - 1600-5368 VL - 69 IS - Part 2 SP - o157, sup-1 - sup-7 PB - Munksgaard CY - Copenhagen AN - OPUS4-27572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Reck, Günter A1 - Radeglia, Reiner A1 - Springer, A. A1 - Schulz, Burkhard T1 - Designed self-assembly of a bimolecular calix[4]resorcinarene capsule held together by hydrogen bonds JF - Journal of molecular structure N2 - The X-ray crystallographic study of the macrocyclic tetrakis-N[N-2-hydroxyethyl-piperazino]calix[4]resorcinarene·3CH3CH2OH·H2O (3) reveals a self-assembled dimeric capsule-like complex held together by an array of intermolecular hydrogen bonds. Pairs of concave molecules associate directly in bowl-to-bowl fashion and enclose an accessible supramolecular cavity of Å3 hosting one water and three ethanol molecules. The supramolecular arrangement displays alternating layers of facing bowls and interlocking lower rim aliphatic moieties. The helical conformation of the 2-hydroxyethyl piperazinomethyl moieties displays chirality of a bimolecular capsule frozen in the solid state. 3 crystallises in the triclinic space group P-1 with two symmetry independent molecules in the asymmetric unit. Two enantiomeric capsules form a racemic pair in the unit cell. KW - Hydrogen bonded molecular capsule KW - Conformational chirality KW - Calix[4]resorcinarenes KW - Crystal structure PY - 2006 DO - https://doi.org/10.1016/j.molstruc.2005.08.027 SN - 0022-2860 SN - 1872-8014 SN - 0377-046X VL - 784 IS - 1-3 SP - 157 EP - 161 PB - Elsevier CY - Amsterdam AN - OPUS4-12241 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -