RESUMEN
A rapid, easy, versatile, simultaneous analytical method based on three-layer extraction and LC-MS/MS was developed for the determination of residual veterinary drugs in livestock and fishery products. In this method, degreasing with n-hexane, partitioning into acetonitrile, and purification by the salting-out effect were simultaneously performed after extraction with acetone aq. It allowed to prepare a test solution without concentrating, transferring, and purification using solid column. Recoveries of quinolones were improved by adjusting acid concentration and adding EDTA-2Naã»2H2O. As a result, 62 analytes for cattle muscle, 63 analytes for cattle fat, 62 analytes for eel, and 65 analytes for salmon met the management criteria of the guideline for validity assessment (Ministry of Health, Labour and Welfare in Japan). Thus, the present method could be useful for a rapid determination of residual veterinary drugs in livestock and fishery products.
Asunto(s)
Peces , Ganado , Drogas Veterinarias , Animales , Cromatografía Liquida , Explotaciones Pesqueras , Japón , Espectrometría de Masas en Tándem , Drogas Veterinarias/análisisRESUMEN
A rapid, sensitive and selective analytical method by LC-MS/MS was developed and validated for the determination of cyclamate in various kinds of foods. The Preparation of test solutions was performed by heat extraction technique in accordance with an official notification method in Japan. We aimed to reduce the matrix effects in LC-MS/MS only by diluting extracts without clean-up using solid phase column. This method was assessed for 30 kinds of foods fortifying cyclamate at the concentration level of 0.5 µg/g. As a result, trueness was 85.0 to 106.6%, repeatability (RSDr) ranged from 1.7 to 9.4%, and within-laboratory reproducibility (RSDwr) ranged from was 4.1 to 9.7%. These date supported the reliability our method. Thus, this method could be useful for a rapid determination of cyclamate in various kinds of foods.
Asunto(s)
Ciclamatos/análisis , Análisis de los Alimentos/métodos , Cromatografía Liquida , Japón , Reproducibilidad de los Resultados , Espectrometría de Masas en TándemRESUMEN
We proposed and developed an exfoliation process for layer-structured NaxCoO2 to prepare CoO nanosheets. Na+ ion exchange by acid treatment was utilized to expand the spacing between the two CoO2 layers in NaxCoO2. Ethylamine was then effectively utilized for the exfoliation of cobalt oxide sheets having nanometer-order thickness and high aspect ratio. CoO nanosheets were observed by TEM micrographs and electron diffraction patterns after drying. Further efforts are needed for the application of exfoliated sheets to an integration process to fabricate self-assembled nanomaterials such as desired layer structures composed of two (or more) kinds of nanosheets.
Asunto(s)
Cobalto/química , Nanotecnología/métodos , Óxidos/química , Sodio/química , Materiales Biocompatibles Revestidos/química , Microscopía de Fuerza Atómica , Microscopía Electrónica , Microscopía Electrónica de Rastreo , Nanoestructuras/química , Nanoestructuras/ultraestructura , Tamaño de la Partícula , Análisis Espectral , Propiedades de Superficie , Difracción de Rayos X , Rayos XRESUMEN
VIDAS ECO is useful as a rapid method for detecting E. coli O157 from food samples, because one can obtain the results within 1 hour by examining the enrichment broth after a 18 hour incubation. In addition, one can handle a large amount of sample, owing to its simplicity. No false negative were recognized in the present experiment and diffuse outbreak samples cases, which confirmed the usefulness of ECO as a screening method. Besides, regarding ECO positive samples, we could confirm by the following day, that they were false positive, by a combined test using an isolation medium after a bead-enzyme-linked immunosorbent assay.