TY - JOUR A1 - Siegel, David A1 - Koch, Matthias A1 - Emmerling, Franziska A1 - Nehls, Irene T1 - Deacetyl tenuazonic acid KW - Deacetyl tenuazonic acid KW - X-ray single crystal diffraction KW - Crystal structure PY - 2009 DO - https://doi.org/10.1107/S1600536809015372 SN - 1600-5368 VL - 65 IS - 6 SP - o1201 PB - Munksgaard CY - Copenhagen AN - OPUS4-19429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Becker, Roland A1 - Koch, Matthias A1 - Buge, Hans-Georg A1 - Nehls, Irene T1 - Entwicklung eines Referenzverfahrens zur Quantifizierung von polychlorierten Biphenylen (PCB) in Kunststoffgranulaten N2 - Im Rahmen eines vom Bundesministerium für Wirtschaft und Arbeit (BMWA) geförderten Projektes wird in Kooperation mit dem Verband deutscher Metallhändler (VDM) ein Verfahren zur Quantifizierung der PCB-Kongenere 28, 52, 101, 138, 153, 180 im Gehaltsbereich von 0,1 bis 20 mg in Kunststoffabfällen aus dem Altkabelrecycling entwickelt und validiert. Dazu werden repräsentative Referenzmaterialien für die Laboranalytik aus Granulaten verschiedener Kabelzerlegeprozesse hergestellt und charakterisiert. Die Methodenentwicklung umfasst mahl-, sieb- und schüttguttechnologische Aspekte sowie den Vergleich unterschiedlicher Extraktionsverfahren und chromatographischer Bedingungen. Das validierte Verfahren sieht die Mahlung der technischen Probe auf eine Kornobergrenze von 0,50 mm gefolgt von Extraktion mit einem unpolaren Lösungsmittel bei einer Einwaage von 4 g und gaschromatographischer Bestimmung vor. Die Bestimmungsgrenzen liegen zwischen 0,01 und 0,08 mg/kg. Bei sorgfältiger Wahl der chromatographischen Bedingungen sind Elektroneneinfang- und massenselektive Detektion (MS) gleichwertig. In Gegenwart größerer Mengen bestimmter Komponenten, die in einigen Kabeln enthalten sind, kann der Einsatz eines MS von Vorteil sein. Drei Referenzmaterialien mit Gehalten der genannten Kongenere zwischen 0,1 bis 5 mg/kg werden in einem abschließenden Ringversuch zur Validierung dieser Methode mit 23 ausgewählten Laboratorien eingesetzt. Dabei ergeben sich für die Quantifizierung dieser Kongenere relative Vergleichsstandardabweichungen zwischen 15 und 33 %. Das Verfahren wird in die europäische Normung (CEN 292 „Characterisation of Waste“) eingebracht. T3 - BAM Forschungsberichtreihe - 270 PY - 2005 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-1810 SN - 978-3-86509-320-5 SN - 0938-5533 VL - 270 SP - 1 EP - 107 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-181 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koch, Matthias T1 - Novel reference materials for mycotoxin analysis T2 - Konferenz zum 50. Jahrestag des JRC's IRMM CY - Geel, Belgium DA - 2010-11-23 PY - 2010 AN - OPUS4-21784 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuner, Maximilian A1 - Kühn, S. A1 - Haase, H. A1 - Meyer, Klas A1 - Koch, Matthias T1 - Cleaving Ergot Alkaloids by Hydrazinolysis - A Promising Approach for a Sum Parameter Screening Method N2 - Ergot alkaloids are mycotoxins formed by fungi of the Claviceps genus, which are some of the most common contaminants of food and feed worldwide. These toxins are a structurally heterogeneous group of compounds, sharing an ergoline backbone. Six structures and their corresponding stereoisomers are typically quantified by either HPLC-FLD or HPLC-MS/MS and the values subsequently summed up to determine the total ergot alkaloid content. For the development of a screening method targeting all ergot alkaloids simultaneously, the alkaloids need to be transferred to one homogeneous structure: a lysergic acid derivative. In this study, two promising cleaving methods—acidic esterification and hydrazinolysis—are compared, using dihydroergocristine as a model compound. While the acidic esterification proved to be unsuitable, due to long reaction times and oxidation sensitivity, hydrazinolysis reached a quantitative yield in 40-60 min. Parallel workup of several samples is possible. An increasing effect on the reaction rate by the addition of ammonium iodide was demonstrated. Application of hydrazinolysis to a major ergot alkaloid mix solution showed that all ergopeptines were cleaved, but ergometrine/-inine was barely affected. Still, hydrazinolysis is a suitable tool for the development of a sum parameter screening method for ergot alkaloids in food and feed. KW - Ergot alkaloids KW - Sum parameter method KW - Hydrazinolysis KW - Esterification PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527508 DO - https://doi.org/10.3390/toxins13050342 VL - 13 IS - 5 SP - 342 PB - MDPI CY - Basel, Switzerland AN - OPUS4-52750 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Merkel, Stefan A1 - Köppen, Robert A1 - Koch, Matthias A1 - Emmerling, Franziska A1 - Nehls, Irene T1 - Ergometrinine N2 - The absolute configuration of ergometrinine, C19H23N3O2 {systematic name: (6aR,9S)-N-[(S)-1-hydroxypropan-2-yl]-7-methyl-4,6,6a,7,8,9-hexahydroindolo[4,3-fg]quinoline-9-carboxamide}, was established based on epimerization reaction of ergometrine, which was followed by preparative HPLC. The non-aromatic ring (ring C of the ergoline skeleton) directly fused to the aromatic rings is nearly planar [maximum deviation = 0.271 (3) Å] and shows an envelope conformation, whereas ring D, involved in an intramolecular N-HN hydrogen bond, exibits a slightly distorted chair conformation. The structure displays undulating layers in the ac plane formed by O-H...O and N-H...O hydrogen bonds. KW - Ergometrinine KW - Ergometrine KW - Ergot alkaloids KW - Indole alkaloids KW - Crystal structure KW - Epimerization PY - 2010 DO - https://doi.org/10.1107/S1600536810030825 SN - 1600-5368 VL - 66 IS - 9 SP - o2275, sup-1 - sup-9 PB - Munksgaard CY - Copenhagen AN - OPUS4-21806 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koch, Matthias T1 - Zearalenone in maize germ oil - a new CRM for food safety T2 - 14th International Symposium on Biological and Environmental Reference Materials (BERM 14) CY - National Harbor, Maryland (USA) DA - 2015-10-11 PY - 2015 AN - OPUS4-34672 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Temgoua Tonleu, Ranil C. A1 - Koch, Matthias T1 - Simulation of the Environmental Degradation of TBBPA by EC-LC-MS N2 - Oxidative degradation processes of tetrabromobisphenol A (TBBPA), a brominated flame retardant (BFR) in wood, plastics and electronics, were investigated by electrochemistry (EC) coupled online to electrospray ionization mass spectrometry (ESI/MS). Oxidative phase I and II metabolites production was achieved using an electrochemical flow-through cell equipped with a boron doped diamond electrode. Structural elucidation and prediction of oxidative metabolism pathways of TBBPA according to type II ipso-substitution were based on retention time, m/z ratio in negative mode and fragmentation pattern. Using the data obtained through high resolution MS analysis and the identification of single electron transfer (SET) as the initial step of a two-electron oxidation provided the necessary information to propose a mechanism for the electrochemical oxidation of TBBPA. Oxidation reactions involving aromatic hydroxylation and β-scission were the main degradation observed when studying the electrochemical behavior of TBBPA. Computational chemistry experiments using density functional theory (DFT) allowed to identify mono-hydroxylated reaction intermediate and dismissed the mechanism involving two concurrent hydroxylation. TBBPA oxidation products were compared to known metabolites of its biological and environmental degradation confirming the ability of electrochemistry to simulate β-scission reactions. T2 - Mass Spectrometry Forum 2024 CY - Vienna, Austria DA - 21.02.2024 KW - Emerging pollutants KW - Chemical characterization KW - Electrochemistry KW - Chemical and material safety KW - Mass spectrometry KW - Environment-material interactions PY - 2024 AN - OPUS4-59571 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwake-Anduschus, C. A1 - Proske, Matthias A1 - Sciurba, E. A1 - Muenzing, K. A1 - Koch, Matthias A1 - Maul, Ronald T1 - Distribution of deoxynivalenol, zearalenone, and their respective modified analogues in milling fractions of naturally contaminated wheat grains N2 - Mycotoxins are among the most abundant contaminants in food and feed worldwide. Therefore, in the EU maximum levels are established, e.g. for the frequently occurring Fusarium toxins deoxynivalenol (DON) and zearalenone (ZEA). Additional to DON and ZEA, modified mycotoxins are present in naturally contaminated grain products contributing significantly to the exposure of humans and animals with mycotoxins. Up to now data on the spatial distribution of many (masked) mycotoxins in the kernels of wheat are missing. The aim of the present study was to investigate the amounts of DON and ZEA as well as their most abundant derivatives DON-3-glucoside (DON-3G), 3- and 15-acetyl-DON, ZEA-14- and 16-glucoside and ZEA-14-sulphate (ZEA-14S) in mill fractions of naturally contaminated wheat batches using HPLC-MS/MS. The investigated distribution pattern in ten milling fractions is comparable among the three investigated different wheat batches. Interestingly, DON and DON-3G were found to be present to similar amounts in all fractions. In bran, the levels were only slightly higher than in the endosperm. By contrast, for ZEA and ZEA-14S a significantly higher amount of toxin is located in the fibre-rich fractions. The relative mass proportion of DON-3G comprises for only between 2.9 and 11.2% of the free DON, while the relative mass proportion of ZEA-14S is estimated to even exceed the amount of free ZEA in certain fractions. Acetylated DON derivatives and ZEA-glucosides were only detected in low amounts. The experimental results show that a significant reduction of the ZEA and ZEA-14S level in wheat flour is feasible by applying milling technology strategies. However, the almost evenly distribution of DON and DON-3G in all fractions does not allow for the technological removal of relevant toxin amounts. Furthermore, the relative share of masked forms was higher for ZEA derivatives than for the DON conjugates in the investigated wheat lots. KW - Mass spectrometry KW - Fusarium mycotoxins KW - Masked mycotoxin KW - Flour extraction KW - Bran PY - 2015 DO - https://doi.org/10.3920/WMJ2014.1818 SN - 1875-0710 SN - 1875-0796 VL - 8 IS - 4 SP - 433 EP - 443 PB - Wageningen Academic Publishers CY - Wageningen AN - OPUS4-33833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siegel, David A1 - Merkel, Stefan A1 - Bremser, Wolfram A1 - Koch, Matthias A1 - Nehls, Irene T1 - Degradation kinetics of the Alternaria mycotoxin tenuazonic acid in aqueous solutions N2 - The degradation kinetics of the Alternaria mycotoxin tenuazonic acid (l-TA) in aqueous buffer were studied over a period of 4 months at different pH levels (3.5 and 7.0) and temperatures (4, 25 and 40°C). l-TA and its degradation products were quantified by newly developed high-performance liquid chromatography methods with UV or electrospray multistage mass spectrometry detection. At pH 3.5, significant degradation occurred at 25 and 40°C, the respective l-TA half-lives being 73.8±0.4 and 14.0±0.1 days. Two degradation processes, epimerization and hydrolysis, were evaluated kinetically. The hydrolytically formed iso-deacetyl TA (iso-DTA, epimeric mixture) was found to be the stable end product of l-TA degradation under the conditions of this study. This indicates that iso-DTA as well as the l-TA epimer u-TA are formed in aqueous beverage matrices. KW - Tenuazonic acid KW - Alternaria KW - Epimerization KW - Degradation KW - Kinetics PY - 2010 DO - https://doi.org/10.1007/s00216-009-3288-5 SN - 1618-2642 SN - 1618-2650 VL - 397 IS - 2 SP - 453 EP - 462 PB - Springer CY - Berlin AN - OPUS4-21373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weiz, S. A1 - Marten, S. A1 - Heinze, J. A1 - Drzymala, Sarah A1 - Koch, Matthias T1 - Unpolarer Analyt, unpolare Matrix: das Mykotoxin Zearalenon in Öl N2 - Mit einer automatisierten Online-Festphasenextraktion ist das Schimmelpilzgift Zearalenon in Speiseöl mit HPLC direkt bestimmbar. Die Probenvorbereitung ist hochselektiv und eignet sich für die Routinekontrolle des EU-Grenzwerts. KW - Mykotoxine KW - HPLC KW - Online-SPE KW - Hydrazine PY - 2013 SN - 1439-9598 SN - 1521-3854 VL - 61 IS - Dezember SP - 1241 EP - 1243 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-29811 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -