RESUMO
HIGHLIGHTS: This study is a significant contribution to L. monocytogenes risk analysis. L. monocytogenes was found in 3.6% of 30,016 analyzed RTE food samples. A food safety criterion of 100 CFU/g was exceeded for 0.3% of the RTE food samples. Salted and cold-smoked fish products were found to be potentially high-risk foods.
Assuntos
Listeria monocytogenes , Animais , Contagem de Colônia Microbiana , Estônia , Contaminação de Alimentos , Microbiologia de Alimentos , Produtos da Carne , PrevalênciaRESUMO
A new scheme for the quantitative determination of traces of fluoroquinolones (FQs), tetracyclines (TCs) and sulfonamides (SAs) in sewage sludge was developed. The compounds were simultaneously extracted from sewage sludge by pressurized liquid extraction (PLE). A novel and effective method for PLE was developed. Solid-phase extraction was used for cleaning up the extracts. Identification and quantification of the compounds was done using high-performance liquid chromatography with electrospray ionization mass spectrometry in selected reaction monitoring mode. The best recovery of FQs and TCs was obtained by using hydrophilic-lipophilic balance cartridges, recoveries ranged 59% for norfloxacin to 82% for ofloxacin and 95% for doxycycline; for SAs strong cation-exchange cartridges were more efficient, recoveries were 96% for sulfamethoxazole and 43% for sulfadimethoxine. Limit of quantification ranged from 0.1 ng/g for SAs to 160 ng/g for tetracycline. Method precision for TCs was 5.06% and 1.12%, and for SAs 0.43% and 2.01%. FQs precision ranged from 0.77% to 1.89%.