RESUMO
The present work is focused on the development/optimization of a comprehensive two-dimensional gas chromatography method, with dual detection [flame ionization (FID) and mass spectrometric], for the simultaneous identification and quantification of mineral-oil contaminants in a variety of food products. The two main classes of contaminants, namely saturated and aromatic hydrocarbons, were previously fractionated on a manually-packed silver silica solid-phase extraction (SPE) cartridge. The quantitative results were compared with those obtained by performing a large volume injection, in a GC-FID system, after the same SPE process and by an on-line liquid-gas chromatography method, with very similar results observed. The presence of a series of unknown compounds, that appeared when using the off-line methods, was investigated using the mass spectrometric data, and were tentatively-identified as esterified fatty acids, most probably derived from vegetable oil based ink.
Assuntos
Cromatografia Gasosa , Análise de Alimentos , Hidrocarbonetos/química , Ácidos Graxos/análise , Hidrocarbonetos/isolamento & purificação , Espectrometria de Massas , Óleo Mineral/química , Óleo Mineral/isolamento & purificação , Óleos de Plantas/química , Nitrato de Prata/química , Extração em Fase SólidaRESUMO
Vaccination is a conventional approach against foot-and-mouth disease (FMD) in pigs. However, failure to elicit an immune response to vaccine has been reported. Our previous investigation showed that ginseng stem and leaf saponins (GSLS) and mineral oil acted synergistically to promote Th1/Th2 immune responses to FMD vaccine in mice. This study was designed to i) find the optimal doses of GSLS in oil-emulsified FMD vaccines to induce immune responses in mice and pigs and ii) to evaluate the effect of oil-emulsified FMD vaccine supplemented with GSLS on the immune responses in pigs, by measuring the serum indirect hemagglutination (IHA) titer and IgG and IgG subclass levels. The GSLS-enhanced immune response to FMD oil-emulsion vaccine depended on the dose of GSLS added to the vaccine. Addition of GSLS at a dose of 40 µg to 2 ml of FMD oil-emulsified vaccine significantly enhanced the humoral immune responses in pigs, when compared to the vaccine without GSLS (P<0.05). The increased antibodies included IgG1 and IgG2. Hence, GSLS and oil adjuvant synergistically promoted the immune responses to vaccination against FMD in pigs, and GSLS could be a promising vaccine additive to improve oil-emulsified veterinary vaccines.
Assuntos
Febre Aftosa/prevenção & controle , Panax/química , Saponinas/química , Vacinas Virais/imunologia , Animais , Anticorpos Antivirais/sangue , Imunidade Humoral , Imunoglobulina G/sangue , Camundongos , Óleo Mineral/química , Óleo Mineral/isolamento & purificação , Óleo Mineral/farmacologia , Folhas de Planta/química , Caules de Planta/química , Saponinas/isolamento & purificação , Saponinas/farmacologia , Suínos , Células Th1/imunologia , Células Th2/imunologia , Vacinas Virais/administração & dosagemRESUMO
Barley straw, an agricultural waste, was chemically modified and evaluated for the removal of emulsified oils from aqueous solution. The chemical modification was performed using NaOH and a cationic surfactant, hexadecylpyridinium chloride monohydrate (CPC). The surface textural and chemical properties of the surfactant modified barley straw (BMBS) were characterized by N(2) adsorption, FT-IR, SEM and water soluble mineral content. The adsorption tests were carried out in batch adsorption system for removal of standard mineral oil (SMO) and canola oil (CO) from water. For both emulsified oils in wastewater, adsorption was found to be strongly related with solution pH. The isotherm study indicated that emulsified oil adsorption on BMBS could be fitted well with the Langmuir model other than Freundlich model. The maximum adsorption capacity for CO and SMO at 25 degrees C determined from the Langmuir isotherm is 613.3 and 584.2 mg g(-1), respectively. Desorption tests in water solution show that oil is strongly bonded with adsorbent and desorption is only about 1-2% in 24 h.
Assuntos
Ácidos Graxos Monoinsaturados/isolamento & purificação , Hordeum/metabolismo , Óleo Mineral/isolamento & purificação , Tensoativos/química , Purificação da Água/métodos , Adsorção , Biotecnologia/métodos , Cátions , Cetilpiridínio/química , Emulsificantes , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura/métodos , Óleo Mineral/análise , Minerais/química , Óleo de Brassica napus , Espectroscopia de Infravermelho com Transformada de Fourier , Água/químicaRESUMO
The main objective of this study was to examine the removal of oil from water by expanded and hydrophobized vermiculite. A pH of 9 showed a higher removal efficiency of oil by vermiculite. Oil removal efficiencies at pH 9 were found to be 79%, 93%, 90%, 57% for standard mineral oil (SMO), Canola oil (CO), Kutwell oil (KUT45), refinery effluent (RE), respectively, in the case of expanded vermiculite, and 56%, 58%, 47%, 43% for SMO, CO, KUT45 and RE, respectively, for hydrophobized vermiculite. Kinetic data satisfied both the Lagergren and Ho models. Equilibrium studies showed that the Langmuir isotherm was the best-fit isotherm for oil removal by both expanded and hydrophobized vermiculite. The data showed a higher adsorptive capacity by the expanded vermiculite compared to the hydrophobized vermiculite. Desorption studies showed that the expanded vermiculite did not desorb oil to the same extent compared to hydrophobized vermiculite. The Freundlich isotherm was the best-fit model for desorption. Expanded vermiculite showed better retention than hydrophobic vermiculite. The results showed that the expanded vermiculite had a greater affinity for oil than hydrophobized vermiculite.