TY - JOUR A1 - Sebald, M. A1 - Gebauer, J. A1 - Koch, Matthias T1 - Diastereoselective synthesis of (±)-trichodiene and (±)-trichodiene-D3 as analytical standards for the on-site quantification of trichothecenes N2 - The ubiquitous Fusarium genus is responsible for the spoilage of vast amounts of cereals and fruits. Besides the economic damage, the danger to human and animal health by the concomitant exposure to mycotoxins represents a serious problem. A large number of Fusarium species produce a variety of different mycotoxins of which the class of trichothecenes are of particular importance due to their toxicity. Being identified as the common volatile precursor during the biosynthesis of trichothecenes, (−)-trichodiene (TD) is considered to be a biomarker for the respective mycotoxin content in food samples. We postulated that the development of a non-invasive, on-site GC-IMS method for the quantification of (−)-trichodiene supplemented with a stationary SIDA headspace GC-MS reference method would allow circumventing the laborious and expensive analyses of individual trichothecenes in large cereal samples. In this work we present the syntheses of the required native calibration standard and an isotope labeled (TD-D3) internal standard. KW - Mycotoxins KW - Volatile marker KW - Food analysis KW - Screening method KW - Mobile analysis PY - 2021 DO - https://doi.org/10.1039/d1ob01778k VL - 19 IS - 45 SP - 9872 EP - 9879 PB - RSC AN - OPUS4-53993 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sebald, M.A. A1 - Gebauer, J. A1 - Sommerfeld, Thomas A1 - Koch, Matthias T1 - First Synthesis of (−)-Altenuene-D3 Suitable as Internal Standard for Isotope Dilution Mass Spectrometry N2 - Metabolites from Alternaria fungi exhibit a variety of biological properties such as phytotoxic, cytotoxic, or antimicrobial activity. Optimization of a literature procedure culminated in an efficient total synthesis of (−)-altenuene as well as a stable isotope-labeled derivative suitable for implementation in a LC-MS/MS method for mycotoxin analysis. KW - Altenuene KW - Alternaria mycotoxins KW - Food safety KW - Isotope-labeled KW - SIDA-LC-MS/MS KW - Suzuki coupling PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-500696 DO - https://doi.org/10.3390/molecules24244563 SN - 1420-3049 VL - 24 SP - 4563 PB - MDPI CY - Basel AN - OPUS4-50069 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siegel, David A1 - Andrae, K. A1 - Proske, Matthias A1 - Kochan, Cindy A1 - Koch, Matthias A1 - Weber, M. A1 - Nehls, Irene T1 - Dynamic covalent hydrazine chemistry as a selective extraction and cleanup technique for the quantification of the Fusarium mycotoxin zearalenone in edible oils N2 - A novel, cost-efficient method for the analytical extraction of the Fusarium mycotoxin zearalenone (ZON) from edible oils by dynamic covalent hydrazine chemistry (DCHC) was developed and validated for its application with high performance liquid chromatography-fluorescence detection (HPLC-FLD). ZON is extracted from the edible oil by hydrazone formation on a polymer resin functionalised with hydrazine groups and subsequently released by hydrolysis. Specifity and precision of this approach are superior to liquid partitioning or gel permeation chromatography (GPC). DCHC also extracts zearalanone (ZAN) but not α-/β-zearalenol or -zearalanol. The hydrodynamic properties of ZON, which were estimated using molecular simulation data, indicate that the compound is unaffected by nanofiltration through the resin pores and thus selectively extracted. The method's levels of detection and quantification are 10 and 30 µg/kg, using 0.2 g of sample. Linearity is given in the range of 10-20,000 µg/kg, the average recovery being 89%. Bias and relative standard deviations do not exceed 7%. In a sample survey of 44 commercial edible oils based on various agricultural commodities (maize, olives, nuts, seeds, etc.) ZON was detected in four maize oil samples, the average content in the positive samples being 99 µg/kg. The HPLC-FLD results were confirmed by HPLC-tandem mass spectrometry and compared to those obtained by a liquid partitioning based sample preparation procedure. KW - Zearalenone KW - Extraction KW - Edible oil KW - Maize KW - Dynamic covalent hydrazine chemistry KW - Hydrazone KW - SPE KW - Hydrodynamic radius KW - HPLC-FLD PY - 2010 DO - https://doi.org/10.1016/j.chroma.2010.02.019 SN - 0021-9673 VL - 1217 IS - 15 SP - 2206 EP - 2215 PB - Elsevier CY - Amsterdam AN - OPUS4-21048 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siegel, David A1 - Blaske, Franziska A1 - Koch, Matthias A1 - Emmerling, Franziska A1 - Nehls, Irene T1 - Deacetyl tenuazonic acid p-toluenesulfonylhydrazone KW - Deacetyl tenuazonic acid KW - Toluenesulfonylhydrazine KW - Hydrazone KW - Crystal structure PY - 2009 DO - https://doi.org/10.1107/S1600536809048958 SN - 1600-5368 VL - E65 IS - 12 SP - o3136 Sup-1 - o3136 Sup-8 PB - Munksgaard CY - Copenhagen AN - OPUS4-20608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siegel, David A1 - Feist, M. A1 - Proske, Matthias A1 - Koch, Matthias A1 - Nehls, Irene T1 - Degradation of the alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking N2 - The stability of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking was investigated by model experiments using a spiked wholemeal wheat flour matrix. For alternariol and alternariol monomethyl ether, but not for altenuene, degradation products, formed through a sequence of hydrolysis and decarboxylation, could be identified in pilot studies. The simultaneous quantification of alternariol, alternariol monomethyl ether, altenuene, and the degradation products was achieved by a newly developed high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) multimethod. The obtained quantitative data indicate that the Alternaria mycotoxins are barely degraded during wet baking, while significant degradation occurs upon dry baking, with the stability decreasing in the order alternariol monomethyl ether > alternariol > altenuene. The novel degradation products could be detected after the wet baking of flour spiked with alternariol and in a sample survey of 24 commercial cereal based baking products. KW - Alternariol monomethyl ether KW - Alternariol KW - Altenuene KW - Degradation KW - Baking KW - Bread KW - HPLC-MS/MS PY - 2010 DO - https://doi.org/10.1021/jf102156w SN - 0021-8561 SN - 1520-5118 VL - 58 IS - 17 SP - 9622 EP - 9630 PB - American Chemical Society CY - Columbus, Ohio AN - OPUS4-21909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - JOUR A1 - Siegel, David A1 - Koch, Matthias A1 - Nehls, Irene T1 - Wiederentdeckung eines alten Bekannten - 2,4-Dinitrophenylhydrazin in der Umweltanalytik KW - Carbonyle KW - Derivatisierung KW - 2,4-Dinitrophenylhydrazin KW - Luft KW - Trinkwasser KW - PET PY - 2009 SN - 0016-3538 IS - Sonderausgabe: Umweltanalytik 2008 SP - 226 EP - 228 PB - GIT-Verlag CY - Darmstadt AN - OPUS4-18615 LA - deu 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 - Siegel, David A1 - Merkel, Stefan A1 - Koch, Matthias A1 - Emmerling, Franziska A1 - Nehls, Irene T1 - 3-{1-[(2,4-Dinitrophenyl)hydrazino]ethylidene}-5-(1-methylpropyl)pyrrolidine-2,4-dione KW - Tenuazonic acid 2,4-dinitrophenylhydrazone KW - X-ray single crystal diffraction KW - Crystal structure PY - 2009 DO - https://doi.org/10.1107/S1600536809012458 SN - 1600-5368 VL - 65 IS - 5 SP - o988 EP - o989 PB - Munksgaard CY - Copenhagen AN - OPUS4-19736 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Siegel, David A1 - Merkel, Stefan A1 - Koch, Matthias A1 - Nehls, Irene T1 - Quantification of the Alternaria mycotoxin tenuazonic acid in beer N2 - Tenuazonic acid (TA) is a major water soluble Alternaria mycotoxin. In the present work, a method for the quantification of TA in beer by liquid chromatography-ion-trap multistage mass spectrometry after derivatization with 2,4-dinitrophenylhydrazine is described. The method is based on a rapid workup procedure and features a LOD of 2 µg/kg without preconcentration using 400 mg of sample. Validation was performed for a working range of 8-500 µg/kg. A total of 43 beers of different brewing styles (pilsener, wheat beer, bock beer, dark beer and alcohol free beer) was analysed. TA was detected in 37 samples, 16 samples were above the LOQ. An average content of 11 µg/kg was found, the highest incidence being 175 ± 13 µg/kg. To our knowledge, this is the first report on the occurrence of TA in beer and beverages in general. KW - Tenuazonic acid KW - Mycotoxin KW - Beer KW - 2,4-Dinitrophenylhydrazine KW - Derivatization KW - Liquid chromatography/electrospray ionisation ion-trap multistage mass Spectrome PY - 2010 DO - https://doi.org/10.1016/j.foodchem.2009.10.070 SN - 0308-8146 VL - 120 IS - 3 SP - 902 EP - 906 PB - Elsevier CY - Amsterdam [u.a.] ; Jena AN - OPUS4-21372 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -