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 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 - Mönch, Bettina A1 - Gebert, Antje A1 - Emmerling, Franziska A1 - Becker, Roland A1 - Nehls, Irene T1 - Koenigs-Knorr reaction of fusel alcohols with methyl (1-bromo-2,3,4-tri-O-acetyl-alpha-D-glucopyranosid)uronate leading to the protected alkyl glucuronides-crystal structures and high resolution 1H and 13C NMR data N2 - Crystal structures and high resolution 1H and 13C NMR spectral data for methyl (alkyl 2,3,4-tri-O-acetyl-β-D-glucopyranosid)uronates (alkyl = methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, i-butyl, n-pentyl, 2-methyl-1-butyl and 3-methyl-1-butyl) are presented. KW - D-Glucuronic acid derivates KW - X-ray analysis KW - High resolution NMR KW - Anomeric configuration KW - Synthesis PY - 2012 DO - https://doi.org/10.1016/j.carres.2012.01.002 SN - 0008-6215 SN - 1873-426X VL - 352 SP - 186 EP - 190 PB - Elsevier CY - Amsterdam AN - OPUS4-25759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - 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 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 - Nehls, Irene A1 - Hanebeck, Olaf A1 - Becker, Roland A1 - Emmerling, Franziska T1 - N-(beta-carboxyethyl)-alpha-isoleucine 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 - 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 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 - 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 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 -