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Certified reference materials (CRM) provide measurements of quality and metrological traceability relative to the International System of Units (SI). The results of a feasibility study for the development of an incurred CRM for the mass fraction of nitrofuran metabolites in chicken muscles are presented in this work. A small-scale batch of material was produced from freeze-dried chicken breast muscles containing residues of 3-amino-2-oxazolidinone (AOZ) and 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) metabolites after the controlled in vivo administration of furazolidone and furaltadone antibiotics. A small-scale batch from a blank matrix, without the metabolites, was also produced. The granulometry, stability of residual moisture content, effect of the treatment by irradiation at 3 kGy, 5 kGy and 7 kGy, and degree of inhomogeneity of the property values and residual moisture were evaluated. All statistical approaches for homogeneity and stability assessments were performed based on the principles of ISO Guide 35:2006.

A simple multiresidue and multiclass procedure is described for the simultaneous determination of anabolic agents and β2-agonists from 4 classes of prohibited substances of illegal use in food-producing animals, according to Council Directive 96/23/EC. The method involves analysis of hydrolysed urinary anabolic compounds using liquid–liquid extraction, with subsequent conversion to trimethylsilylether derivatives that are analysed by GC-MS/MS. The oven was set to an initial temperature of 140°C, was increased at a rate of 10°C/min to 300°C, and was held 3 min using an Ultra-1 capillary column. Optimization tests demonstrated good peak resolution and shape for all compounds. A pre-validation study was conducted to obtain an analytical test curve, which showed adequate results for all analytes. Cochran's test (C calculated

Objetivou-se neste trabalho identificar Enterobacteriaceae da microbiota intestinal de frangos de corte que foram submetidos a quatro tratamentos diferentes com nitrofuranos, do 15° ao 23° dia de vida. Foram coletadas, por via cloacal, amostras fecais atraves de suabes estereis de 52 aves da linhagem Cobb, em seguida transportados em meio Cary-blair para isolamento e identificacao dos generos e especies atraves das provas bacteriologicas convencionais e atraves dos sistemas Bactray I e II. Os generos e especies isolados nos tratamentos com nitrofuranos e no controle foram: Citrobacter spp., Escherichia coli, Escherichia fergusonii, Escherichia Hermannii, Enterobacter aerogenes, Enterobacter aminigenus, Enterobacter cloacae, Enterobacter sakazakii, Hafnia alvei, Klebsiella oxytoca, Klebsiella ozaenae, Klebsiella pneumoniae, Morganella morganii, Proteus spp e Pseudomonas luteola. De todos os tratamentos, o maior percentual de Escherichia coli isoladas ocorreu no grupo controle, sendo este tambem o que apresentou menor diversidade de micro-organismos, com apenas dois generos identificados. O uso de antimicrobianos na racao nos demais tratamentos pode ser uma explicacao para o desequilibrio da microbiota normal do intestino, resultando em um aumento populacional de outras enterobacteriaceas.