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 - Rasenko, Tatjana A1 - Koch, Matthias A1 - Nehls, Irene T1 - Determination of the Alternaria mycotoxin tenuazonic acid in cereals by high-performance liquid chromatography-electrospray ionization ion-trap multistage mass spectrometry after derivatization with 2,4-dinitrophenylhydrazine N2 - Tenuazonic acid (TA) is a major Alternaria mycotoxin. In the present work a novel approach for the detection of TA in cereals by liquid chromatography–ion-trap multistage mass spectrometry after derivatization with 2,4-dinitrophenylhydrazine is described. The product of the derivatization reaction and its major MS2 fragments were characterised by Fourier transform-ion cyclotron resonance tandem mass spectrometry. Without preconcentration, the established method features a limit of detection of 10 µg/kg using 2 g of sample in a rapid workup procedure. Accuracy, precision and linearity were evaluated in the working range of 50–5000 µg/kg. TA was detected in 13 and quantified in 3 out of 27 cereal samples obtained from a local supermarket, the average content being 49 µg/kg (highest incidence: 851 ± 41 µg/kg). KW - Tenuazonic acid KW - 2,4-Dinitrophenylhydrazine KW - Derivatization KW - Liquid chromatography-electrospray ionization ion-trap multistage mass spectrome KW - Cereals PY - 2009 DO - https://doi.org/10.1016/j.chroma.2009.03.063 SN - 0021-9673 VL - 1216 IS - 21 SP - 4582 EP - 4588 PB - Elsevier CY - Amsterdam AN - OPUS4-19382 LA - deu 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 - 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 - Köppen, Robert A1 - Koch, Matthias A1 - Siegel, David A1 - Merkel, Stefan A1 - Maul, Ronald A1 - Nehls, Irene T1 - Determination of mycotoxins in foods: current state of analytical methods and limitations N2 - Mycotoxins are natural contaminants produced by a range of fungal species. Their common occurrence in food and feed poses a threat to the health of humans and animals. This threat is caused either by the direct contamination of agricultural commodities or by a "carry-over" of mycotoxins and their metabolites into animal tissues, milk, and eggs after feeding of contaminated hay or corn. As a consequence of their diverse chemical structures and varying physical properties, mycotoxins exhibit a wide range of biological effects. Individual mycotoxins can be genotoxic, mutagenic, carcinogenic, teratogenic, and oestrogenic. To protect consumer health and to reduce economic losses, surveillance and control of mycotoxins in food and feed has become a major objective for producers, regulatory authorities and researchers worldwide. However, the variety of chemical structures makes it impossible to use one single technique for mycotoxin analysis. Hence, a vast number of analytical methods has been developed and validated. The heterogeneity of food matrices combined with the demand for a fast, simultaneous and accurate determination of multiple mycotoxins creates enormous challenges for routine analysis. The most crucial issues will be discussed in this review. These are (1) the collection of representative samples, (2) the performance of classical and emerging analytical methods based on chromatographic or immunochemical techniques, (3) the validation of official methods for enforcement, and (4) the limitations and future prospects of the current methods. KW - Mycotoxins and fungal metabolites KW - Food KW - Rapid and validated methods KW - Regulations KW - Sampling KW - Multi-mycotoxin determination PY - 2010 DO - https://doi.org/10.1007/s00253-010-2535-1 SN - 0175-7598 VL - 86 IS - 6 SP - 1595 EP - 1612 PB - Springer CY - Berlin AN - OPUS4-21184 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 - 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 -