Vier neue Referenzmaterialien zum chemischen Nachweis von Acrylamid in Knäckebrot, Schwefel in Benzin, von polyzyklischen aromatischen Kohlenwasserstoffen und von Legierungen in Akkus stellt die BAM vor. Diese Referenzmaterialien sind durch die BAM zertifiziert und durch das Europäische Referenzmaterialien Programm ERM auf den Markt gebracht.
The degradation and epimerization of ergot alkaloids (EAs) in rye flour were investigated after baking cookies and subsequently subjecting them to an in vitro digestion model. Different steps of digestion were analyzed using salivary, gastric, and duodenal juices. The degradation and bidirectional conversion of the toxicologically relevant (R)-epimers and the biologically inactive (S)-epimers for seven pairs of EAs were determined by a HPLC method coupled with fluorescence detection. Baking cookies resulted in degradation of EAs (2–30 %) and a shift in the epimeric ratio toward the (S)-epimer for all EAs. The applied digestion model led to a selective toxification of ergotamine and ergosine, two ergotamine-type EAs. The initial percentage of the toxic (R)-epimer in relation to the total toxin content was considerably increased after digestion of cookies. Ergotamine and ergosine increased from 32 to 51 % and 35 to 55 %, respectively. In contrast, EAs of the ergotoxine type (ergocornine, α- and β-ergocryptine, and ergocristine) showed an epimeric shift toward their biologically inactive (S)-epimers. Further experiments indicated that the selective epimerization of ergotamine EAs occurs in the duodenal juice only. These results demonstrate that toxification of EAs in the intestinal tract should be taken into consideration.
Wenn in einem Lebensmittel keine Schimmelpilzgifte nachweisbar sind, muss das nicht bedeuten, dass keine enthalten sind. Prozesse der Lebensmittelverarbeitung, etwa das Mälzen in der Brauerei, führen dazu, dass Glucoside oder Sulfate der Toxine entstehen. Sie sind wenig charakterisiert und analytisch bisher kaum fassbar.
The certification of a boron carbide reference material for chemical composition is described. The mass fractions of 16 elements and two boron species are certified in an international interlaboratory comparison with 35 participating laboratories from six different countries. Beside chemical characterization the certification process includes homogeneity and stability testing of the candidate material boron carbide (type F360, 305M422). Details of the analytical methods used for chemical characterization and of the calculation of the uncertainties of the certified mass fractions are given. The new reference material ERM®-ED102 with certified mass fractions of 18 parameters (elements and species) and of the amount fraction of the isotope 10B is a valuable tool for laboratories working in the field of advanced ceramic materials analysis to improve their analytical results.
Production of three certified reference materials for the sulfur content in gasoline (petrol)
(2007)
Directive 2003/17/EC of the European Parliament and the European Council stipulates that petrol (gasoline) with a total sulfur content below 10 mg kg-1 must be available in all European Union member states by 2009. Three certified reference materials were produced in support of this directive in a joint effort of the members of the European Reference Materials Initiative (ERM). Two of the materials were made from commercial petrol, while the third one was prepared from a blend of commercial petrols. Relative between-ampule heterogeneity of the materials was quantified and found to be below 2.5%. Potential degradation during storage and dispatch was quantified, and shelf lives based on these values were set. The three materials were characterized by three institutes using different variants of isotope-dilution mass spectrometry. The results from the three institutes were combined, and the final uncertainties of the respective sulfur mass fractions were estimated including contributions from heterogeneity, stability, and characterization. The following mass fractions were derived: ERM-EF211, 48.8 ± 1.7 mg kg-1; ERM-EF212, 20.2 ± 1.1 mg kg-1; and ERM-EF213, 9.1 ± 0.8 mg kg-1.
Deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN) are toxic secondary metabolites produced by several species of Fusarium fungi. These mycotoxins are often found together in a large variety of cereal-based foods, which are regulated by maximum content levels of DON and ZEN. To date, suitable certified reference materials (CRM) intended for quality control purposes are lacking for these Fusarium mycotoxins. In order to overcome this lack, the first CRM for the determination of DON, NIV and ZEN in naturally contaminated wheat flour (ERM®-BC600) was developed in the framework of a European Reference Materials (ERM®) project. This article describes and discusses the whole process of ERM®-BC600 development, including material preparation, homogeneity and stability studies, and an interlaboratory comparison study for certification. A total of 21 selected expert laboratories from different European countries with documented expertise in the field of mycotoxin analysis took part in the certification study using various gas and liquid chromatographic methods. The certified values and their corresponding expanded uncertainties (k=2) were assigned in full compliance with the requirements of ISO Guide 35 and are as follows: 102±11 µgkg-1 for DON, 1000±130 µgkg-1 for NIV and 90±8 µgkg-1 for ZEN.
Die zuverlässige Überwachung geltender Mykotoxin-Grenzwerte ist elementarer Bestandteil von Lebensmittelsicherheit und Verbraucherschutz. Durch die zunehmende Bedeutung der Qualitätssicherung ist auch die Nachfrage an zertifizierten Referenzmaterialien (ZRM) in den letzten Jahren deutlich gestiegen. Dem steht derzeit jedoch nur eine sehr begrenzte Auswahl geeigneter ZRM gegenüber.