Lohrey L.,University of Munster |
Marschik S.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
Cramer B.,University of Munster |
Humpf H.-U.,University of Munster
Journal of Agricultural and Food Chemistry | Year: 2013
Tenuazonic acid is a fungal secondary metabolite that is produced by a number of Alternaria species and is therefore a natural contaminant of food and feed samples. This paper describes a new strategy for the efficient and economical large-scale synthesis of the isotopically labeled internal standard 13C2-tenuazonic acid via a three-step procedure. Furthermore, a new reliable and quick method based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) cleanup is presented for the determination of tenuazonic acid in food and feed samples utilizing high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) by application of the stable isotope dilution analysis. This new method has a limit of detection (LOD) of 0.86 μg/kg and a limit of quantitation (LOQ) of 2.89 μg/kg. In total 26 tomato samples and 4 bell pepper samples from the German market were analyzed. Tenuazonic acid was found in each sample with levels from 3 to 2330 μg/kg. © 2012 American Chemical Society.
Richter A.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
Sting R.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
Popp C.,Tierseuchenkasse Baden Wurttemberg |
Rau J.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
And 4 more authors.
Epidemiology and Infection | Year: 2012
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) have been isolated from a number of livestock species and persons involved in animal production. We investigated the prevalence of LA-MRSA in fattening turkeys and people living on farms that house fattening turkeys. Eighteen (90%) of 20 investigated flocks were positive for MRSA, and on 12 of the farms 22 (373%) of 59 persons sampled were positive for MRSA. People with frequent access to the stables were more likely to be positive for MRSA. In most flocks MRSA that could be assigned to clonal complex (CC) 398 were detected. In five flocks MRSA of spa-type t002 that is not related to CC398 were identified. Moreover, other methicillin-resistant Staphylococcus spp. were detected on 11 farms and in eight people working on the farms. © Copyright Cambridge University Press 2012.
Vollmer A.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
Biedermann M.,Official Food Control Authority of the Canton of Zurich |
Grundbock F.,Official Food Control Authority of the Canton of Zurich |
Ingenhoff J.-E.,Official Food Control Authority of the Canton of Zurich |
And 3 more authors.
European Food Research and Technology | Year: 2011
From the German market, 119 samples of dry food were analyzed for the migration of mineral oil. The products selected were packed in paperboard boxes and intended for storage for extended periods of time at ambient temperature. The 0.6 mg/kg limit for mineral oil saturated hydrocarbons (MOSH) derived from the WHO/JECFA evaluation was frequently exceeded by a factor of 10-100. Typically, 10-20% of the migrating mineral oil consisted of aromatic hydrocarbons (MOAH). Most samples were merely 2-3 months old and far from the end of their shelf life (usually 1-3 years). From the assumption that about 70% of the MOSH and MOAH which are eluted from GC up to the C 24 n-alkane (
Pantchev A.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
Sting R.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
Bauerfeind R.,Justus Liebig University |
Tyczka J.,Chemisches und Veterinaruntersuchungsamt Karlsruhe |
Sachse K.,Friedrich Loeffler Institute Jena
Comparative Immunology, Microbiology and Infectious Diseases | Year: 2010
The aim of the present study was to analyse the occurrence of chlamydiae in several mammalian host species. Clinical samples that previously tested positive in a Chlamydiaceae-specific real-time PCR were retested using six species-specific real-time PCR assays to identify the chlamydial species involved. Chlamydophila (Cp.) abortus was the agent most frequently found in cattle, sheep, horses, goats, and pigs. Detection in cattle of Cp. psittaci (11% of samples) and Chlamydia (C.) suis (9%), as well as Cp. psittaci in a goat sample was somewhat unexpected. DNA of two different chlamydiae was identified in 56 (12.7%) of 440 samples tested. Cp. felis was the predominant species found in cats, while in guinea pigs and rabbits only Cp. caviae was detected. Interestingly, the latter two pathogens were also identified in samples from dogs. The data show that mixed chlamydial infections are not rare and suggest an extended host range of individual species. L'objectif de la présente étude est d'analyser l'occurrence de chlamydiae et ce, dans plusieurs espèces mammaliennes hôtes. Des échantillons cliniques, préalablement confirmés positifs par PCR en temps réel spécifique de la famille des Chlamydiaceae, ont été de nouveau testés via six PCR en temps réel espèces-spécifiques. Ainsi, il en résulte que Chlamydophila (Cp.) abortus est fréquemment retrouvé chez les bovins, moutons, chevaux, chèvres et cochons. La détection de Cp. psittaci and Chlamydia (C.) suis chez les bovidés (11% et 9% respectivement) ainsi que de Cp. psittaci dans un échantillon dóovidé se révèle quelque peu inattendu. Sur 440 échantillons testés, 56 (soit 12,7%) contiennent l'ADN de deux espèces différentes de chlamydiae. Cp. felis représente l'espèce dominante chez le chat alors que Cp. caviae est présente uniquement chez les cobaye et lapin. Curieusement, ces deux pathogènes sont également détectés dans des échantillons d'origine canine. Les données tendent à démontrer que les infections simultanées par différentes espèces chlamydiales sont rarement des cas isolés et suggèrent dès lors d'étendre la gamme d'hôtes des espèces individuelles. © 2009 Elsevier Ltd.
Weisshaar R.,Chemisches und Veterinaruntersuchungsamt Stuttgart |
Perz R.,Chemisches und Veterinaruntersuchungsamt Stuttgart
European Journal of Lipid Science and Technology | Year: 2010
Discrepancies in the analysis of 3-chloropropane-1,2-diol (3-MCPD) esters can be explained by the hypothesis that in some refined oils significant amounts of fatty acid esters of glycidol (glycidyl esters) are present in addition to 3-MCPD esters. Glycidyl esters were separated from triacylglycerols by gel permeation chromatography (GPC) and detected by gas chromatography-mass spectrometry (GC-MS). Six samples of palm oil and palm oil-based fats were analyzed by GPC and GC-MS. In chromatograms of all samples, significant peaks, retention time and mass spectra in conformity with self-synthesized glycidyl palmitate and glycidyl oleate were detectable. Quantification of individual glycidyl esters was not possible because of a lack of pure standards. Concentration of ester-bound glycidol in different samples of fats and oils was estimated using an indirect difference method. Glycidyl esters could be detected only in refined, but not in crude or native, fats and oils. The highest concentrations were detected in palm oil and palm oil-based fats. In a palm oil sample, glycidyl ester concentration varied according to different deodorization parameters, temperature, and time, while 3-MCPD ester concentration was relatively constant, indicating that mitigation of glycidyl esters possibly may be achieved by optimizing refining parameters. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.