Visando analizar resíduos de metribuzin em amostras de solo, precisamos usar métodos de extração especiais e adequados com alta eficiência. Cinco métodos de extração simples e rápidos (extração em fase sólida (SPE) com balanço hidrofílico-lipofílico (HLB), SPE com nanotubos de carbono de paredes múltiplas (MWCNTs), ultrassom, método quick, easy, cheap, effective, rugged and safe (QuECheRS) e extração líquido-sólido) acoplado a cromatografia gasosa foram usados na análise de resíduos do herbicida metribuzin em solos. Valores médios de recuperação do analito foram > 80%. Os extratos foram analizados por um sistema de cromatografia gasosa (GC) equipado com um detector de captura de elétrons (ECD). A ordem de valores médios de recuperação de metribuzin pelos cinco métodos de extração é: SPE com HLB > SPE com MWCNTs > ultrassom > QuECheRS > extração líquido-sólido. A recuperação média do analito depende do tipo de solo. Os resultados deste estudo mostram que o método de extração SPE com HLB é a melhor opção para extrair metribuzin de solos selecionados.

With a view to analyze metribuzin residues in soil samples, we need to use special and suitable extraction methods with high efficiency. Five simple and rapid extraction methods (solid phase extraction (SPE) with hydrophilic-lipophilic balance (HLB), SPE with multi-walled carbon nanotubes (MWCNTs), ultrasonic, quick, easy, cheap, effective, rugged and safe (QuECheRS) method, and liquid-solid extraction) coupled to gas chromatography were used for the analysis of metribuzin herbicide residues in soils. Mean recovery values of analyte were > 80%. Extracts were analyzed by a gas chromatographic (GC) system equipped with an electron capture detector (ECD). The order of mean recovery values of metribuzin for the five extraction methods is: SPE with HLB > SPE with MWCNTs > ultrasonic > QuECheRS > liquid-solid extraction. Mean recovery of analyte depends on the type of soil. The results of this study show that SPE with HLB extraction method is the best option for extracting metribuzin in selected soils.

Antibacterial properties and chemical characterization of the essential oils from summer savory (Satureja hortensis) extracted by microwave-assisted hydrodistillation (MAHD) were compared with those of the essential oils extracted using the traditional hydrodistillation (HD) method. While MAHD at 660 W required half as much time as HD needed, similar antibacterial efficacies were found from the essential oils obtained by the two extraction methods on two food pathogens (Staphylococcus aureus, a gram positive bacterium, and Escherchia coli, a gram negative bacterium). Also, as it was the case with the essential oils extracted by HD, that of MAHD indicated greater influence on S. aureus than on E. coli. The compositions of the extracted essential oils were also studied using GC-MS analysis. The same components with negligible differences in their quantities were found in the extracted essential oils using the two methods outlined above. Overall, to reduce the extraction time, MAHD can be applied at higher microwave levels without any compromise in the antibacterial properties of the essential oils extracted.

The immobilization of Saccharomyces cerevisiae DSM 70424, Saccharomyces ludwigii DSM 3447 and Saccharomyces rouxii DSM 2531 on brewer's spent grain and then ethanol production and sugar consumption of these immobilized yeasts were investigated. The aim of this study was to investigate the abilities of these three immobilized yeasts for producing alcohol for brewing at two temperatures (7 and 12 °C) using two different sugar levels (one at original level supplied in the brewery and one with 2.5% (w/v), added glucose to the wort). Increasing both parameters resulted in higher alcohol production by all the yeasts studied. At 7 °C and with original wort density the ethanol content at the end of fermentation was 2.7% (v/v) for S. cerevisiae, 1.7% for S. ludwigii and 2.0% for S. rouxii. After the addition of 2.5% (w/v) glucose at the same temperature (7 °C), the alcohol production was increased to 4.1, 2.8 and 4.1%, respectively. Similar improvements were observed when the fermentation was carried out at 12 °C with/without the addition of glucose to the wort. However, temperature indicated greater influence on S. ludwigii than did on S. rouxii and S. cerevisiae. The immobilization as carried out in this study impacted both S. ludwigii and S. rouxii in a way that they could consume maltose under certain conditions.