TY - JOUR A1 - Reck, Günter A1 - Becker, Roland A1 - Walther, G. T1 - Crystal structures of two polymorphic forms of bis-(zinc-dibutyldithiopercarbamate) JF - Zeitschrift für Kristallographie PY - 1995 SN - 0044-2968 VL - 210 SP - 769 EP - 774 PB - Oldenbourg CY - München AN - OPUS4-14852 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solvent the IR-spectrometric determination of total petrol hydrocarbon (TPH) in soil according to ISO/TR 11046 has been replaced by gas chromatography/flame ionisation detection (GC/FID) after extraction with a halogen-free solvent according to ISO/DIS 16703:2001.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 - 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 - 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 - 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 - 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 - 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 - Bremser, Wolfram A1 - Becker, Roland A1 - Kipphardt, Heinrich A1 - Lehnik-Habrink, Petra A1 - Panne, Ulrich A1 - Töpfer, Antje T1 - Stability testing in an integrated scheme JF - Accreditation and quality assurance N2 - ISO Guide 35 deals with RM stability issues and scrutinizes the evaluation of stability testing results under the assumption that either there is no trend at all (a rather rare situation), or any observed deterministic change is insignificant and thus can be neglected. However, market demands for reliable reference materials are obviously not limited to stable or at least seemingly stable materials. In many analytical applications, analytes and measurands under consideration are known, or at least suspected, to be unstable on time scales that may vary widely from measurand to measurand. The Federal Institute for Materials Research and Testing (BAM) has developed (and successfully uses) an integrated approach in its certification practice. The approach is based on an initial stability study and subsequent post-certification monitoring. Data evaluation is model-based and takes advantage of all information collected in the stability testing scheme(s). It thus allows one to deal with any kind of instability observed, to assess limiting time intervals at any stress condition in the range tested, to estimate a final expiry date for materials with detected instabilities or the maximum admissible re-testing interval for seemingly stable materials, and to assess maximum admissible stress loads during delivery of the material to the customer. The article describes (and exemplifies) typical study layout, the model selection, and the integrated data assessment. KW - Certified reference materials KW - Stability KW - Shelf life KW - Arrhenius model KW - ERM PY - 2006 DO - https://doi.org/10.1007/s00769-006-0152-6 SN - 0949-1775 SN - 1432-0517 VL - 11 IS - 10 SP - 489 EP - 495 PB - Springer CY - Berlin AN - OPUS4-14063 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 - Becker, Roland A1 - Koch, Matthias A1 - Lehnik-Habrink, Petra A1 - Nehls, Irene T1 - Quantification of polychlorinated biphenyls in plastic granulates from the recycling of cables - Reference materials and interlaboratory comparison JF - Chemosphere N2 - A procedure for the quantification of the PCB marker congeners 28, 52, 101, 138, 153, 180 in plastic waste form the recycling of cables in the range of content between 0.1 mg kg-1 and 20 mg kg-1 was validated. Representative reference materials for laboratory analyses were produced using granulates from different recycling processes. The method development included aspects of grinding, sieving, homogenising as well as the comparison of extraction methods and chromatographic conditions. The validated procedure foresees grinding of the technical sample to an upper particle size limit of 0.50 mm followed by extraction with an unpolar solvent such as n-hexane and gas chromatographic determination. LOD and LOQ for individual congeners ranged between 0.01 mg kg-1 and 0.08 mg kg-1. Electron capture detection (ECD) and mass selective detection (MS) were equivalent if chromatographic conditions were appropriately selected. The application of MS was advantageous in presence of significant amounts of interfering components which have been found in some cables. Three reference materials containing the marker congeners in the range of 0.1 mg kg-1–5 mg kg-1 were submitted to a final validation intercomparison with 23 selected field laboratories using the developed method. Relative reproducibility standard deviations varied between 15% and 33%. KW - PCB KW - Waste KW - Analysis KW - Method validation KW - Standardisation PY - 2006 DO - https://doi.org/10.1016/j.chemosphere.2006.02.035 SN - 0045-6535 SN - 0366-7111 VL - 65 IS - 9 SP - 1652 EP - 1659 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-14050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Emmerling, Franziska A1 - Kohl, Anka A1 - Becker, Roland T1 - Delta-Hexabromocyclododecane JF - Acta crystallographica E N2 - (1R,2S,5R,6S,9S,10R)-Hexabromocyclododecane (C12H18Br6, d-HBCD) was crystallized from acetonitrile. The C—Br distances range from 1.962 (8) to 1.982 (8) Å and intermolecular Br...Br contacts contribute to the formation of layers. PY - 2007 DO - https://doi.org/10.1107/S1600536807026396 SN - 1600-5368 VL - 63 IS - 7 SP - o3105 PB - Munksgaard CY - Copenhagen AN - OPUS4-15048 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 - 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 - 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 - 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 - Dorgerloh, Ute A1 - Becker, Roland A1 - Nehls, Irene T1 - Determination of volatile organic sulfur compounds in contaminated groundwater JF - Environmental chemistry letters N2 - A practical method for the quantification of total purgeable organic sulfur (POS) in highly contaminated groundwater is described. Volatile organic sulfur compounds (VOSC) are purged from the water samples by a stream of oxygen and combusted. The emerging sulfur dioxide is absorbed in H2O2 and converted to sulfate which is quantified by ion chromatography and reported as mass sulfur equivalent. The overall limit of quantification is 0.03 mg l–1. The content of POS is balanced with the total VOSC determined by GC-AED after liquid–liquid extraction. Separate determination of the non-volatile organic sulfur compounds by direct combustion of the water sample and adsorption to charcoal yielded a mass balance of the total sulfur content. Semi-quantitative GC-MS after purge & trap accumulation revealed that the VOSC mixture is composed of C1–C4 alkyl sulfides. The implementation of the developed methodology for the quantification of VOSC as potential catalyst poison in a cleaning plant for groundwater contaminated with volatile haloorganics (VOX) is presented. KW - Contamination KW - Remediation KW - Summation parameter KW - Combustion KW - Ion chromatography KW - GC-AED KW - GC-MS PY - 2008 UR - http://www.springerlink.com/content/8612g42hwj7130g8/fulltext.pdf DO - https://doi.org/10.1007/s10311-007-0117-y SN - 1610-3653 SN - 1610-3661 VL - 6 IS - 2 SP - 101 EP - 106 PB - Springer CY - Berlin AN - OPUS4-16360 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Köppen, Robert A1 - Becker, Roland A1 - Jung, Christian A1 - Nehls, Irene T1 - On the thermally induced isomerisation of hexabromocyclododecane stereoisomers JF - Chemosphere N2 - The interconversion of the stereoisomers contained in technical 1,2,5,6,9,10-hexabromocyclododecane, a major brominated flame retardant increasingly found in the environment and in biota, was investigated at elevated temperatures. The application of pure enantiomers of the three constituents α-, β-, and γ-HBCD enabled the unambiguous elucidation of the individual isomerisation reactions as well as the quantification of all respective rate constants. At 160 °C the rate constants range over two orders of magnitude from 1.50 × 10-3 to 1.88 × 10-5 mol(%) s-1. A preliminary mechanistic explanation for the differences of the rate constants which govern the composition of HBCD diastereomers at equilibrium is given. KW - Flame retardant KW - Diastereomers KW - Enantiomers KW - Rearrangement KW - Kinetics KW - HBCD PY - 2008 DO - https://doi.org/10.1016/j.chemosphere.2007.11.009 SN - 0045-6535 SN - 0366-7111 VL - 71 IS - 4 SP - 656 EP - 662 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-17753 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -