<?xml version="1.0" encoding="utf-8"?>
<export-example>
  <doc>
    <id>30126</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>45</pageFirst>
    <pageLast>52</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1</issue>
    <volume>7</volume>
    <type>article</type>
    <publisherName>Wageningen Academic Publishers</publisherName>
    <publisherPlace>Wageningen</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Preparation of 13C-labelled cis-zearalenone and its application as internal standard in stable isotope dilution analysis</title>
    <abstract language="eng">Pure U-[13C18]-labelled cis-zearalenone (cis-ZEA) has been prepared and characterised as internal standard (ISTD) for a reliable quantification of cis-ZEA in contaminated food and feed products. The cis-isomer of the naturally trans-configurated Fusarium mycotoxin zearalenone is often neglected. However, isomerisation easily occurs by exposure of ZEA to (UV-)light. Thus, the applicability of the new cis-ZEA ISTD was demonstrated in a long-term isomerisation study comparing naturally trans-ZEA-contaminated edible oil with spiked edible oil. To estimate the benefits of the newly prepared cis-ZEA ISTD, various approaches to quantify cis-ZEA by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) were compared. As a result, a significant bias was revealed if no appropriate cis-ZEA standards are used. Furthermore, the new ISTD was applied to the analysis of 15 edible oils by stable isotope dilution analysis in combination with HPLC-electrospray ionisation-MS/MS. One of the maize germ oils showed the presence of cis-ZEA above LOD (&gt;0.3 µg/kg), whereas two out of 15 maize germ oils were found to be contaminated with trans-ZEA (range 17.0-31.0 µg/kg).</abstract>
    <parentTitle language="eng">World mycotoxin journal</parentTitle>
    <identifier type="old">33076</identifier>
    <identifier type="doi">10.3920/WMJ2013.1610</identifier>
    <identifier type="issn">1875-0710</identifier>
    <identifier type="issn">1875-0796</identifier>
    <enrichment key="date_peer_review">10.02.2014</enrichment>
    <author>Sarah Drzymala</author>
    <author>Juliane Riedel</author>
    <author>Robert Köppen</author>
    <author>L.-A. Garbe</author>
    <author>Matthias Koch</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>ZEA</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Zearalenone</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Isomerisation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Occurrence</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Edible oil</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>SIDA</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>HPLC-MS/MS</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Quantification</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>LC-MS/MS</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>27375</id>
    <completedYear/>
    <publishedYear>2012</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>11733</pageFirst>
    <pageLast>11740</pageLast>
    <pageNumber/>
    <edition/>
    <issue>47</issue>
    <volume>60</volume>
    <type>article</type>
    <publisherName>American Chemical Society</publisherName>
    <publisherPlace>Columbus, Ohio</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Photochemical trans-/cis-isomerization and quantitation of zearalenone in edible oils</title>
    <abstract language="eng">The emphasis of the present work was to investigate the photochemical conversion of trans- to cis-zearalenone in edible oils under real-life conditions. For quantitation purposes a cis-zearalenone standard was synthesized and characterized for its identity and purity (≥95%) by 1H NMR, X-ray crystallography, HPLC fluorescence and mass spectrometric detection. In a sample survey of 12 edible oils (9 corn oils, 3 hempseed oils) from local supermarkets all corn oils contained trans-zearalenone (median 194 µg/kg), but no cis-zearalenone was detected. For alteration studies trans-zearalenone contaminated corn oils were exposed to sunlight over 4 and 30 weeks, revealing an obvious shift toward cis-zearalenone up to a cis/trans ratio of 9:1 by storage in colorless glass bottles. Irradiation experiments of trans-zearalenone in different organic solvents confirmed the preferred formation of cis-zearalenone possibly caused by entropic effects rather than by enthalpic entities as investigated by quantum chemical and classical force field simulations.</abstract>
    <parentTitle language="eng">Journal of agricultural and food chemistry</parentTitle>
    <identifier type="old">30185</identifier>
    <identifier type="doi">10.1021/jf3037775</identifier>
    <identifier type="issn">0021-8561</identifier>
    <identifier type="issn">1520-5118</identifier>
    <enrichment key="date_peer_review">12.12.2012</enrichment>
    <author>Robert Köppen</author>
    <author>Juliane Riedel</author>
    <author>Matthias Proske</author>
    <author>Sarah Drzymala</author>
    <author>Tatjana Rasenko</author>
    <author>V. Durmaz</author>
    <author>M. Weber</author>
    <author>Matthias Koch</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fusarium mycotoxins</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Food</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Analysis</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Occurrence</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
</export-example>
