Search results for "Cromatografia"
showing 10 items of 18 documents
Novel multimetabolite prediction of walnut consumption by a urinary biomarker model in a free-living population: the PREDIMED study.
2014
The beneficial impact of walnuts on human health has been attributed to their unique chemical composition. In order to characterize the dietary walnut fingerprinting, spot urine samples from two sets of 195 (training) and 186 (validation) individuals were analyzed by an HPLC-q-ToF-MS untargeted metabolomics approach, selecting the most discriminating metabolites by multivariate data analysis (VIP ≥ 1.5). Stepwise logistic regression analysis was used to design a multimetabolite prediction biomarker model. The global performance of the model and each included metabolite in it was evaluated by receiver operating characteristic curves, using the area under the curve (AUC) values. Dietary expos…
Una rapida metodica di estrazione del 2-dodecilciclobutanone per la identificazione tramite GC/MS di alimenti irradiati contenenti grassi
2008
Improving detection limits for organotin compounds in several matrix water samples by derivatization-headspace-solid-phase microextraction and GC-MS.
2010
Triethyltin, tributyltin, diphenyltin and triphenyltin were selected as model compounds. The method is based on in situ ethylation and simultaneous headspace-solid-phase microextraction (HS-SPME) and gas chromatographic-mass spectrometry analysis (GC-MS). The extraction procedure was optimized studying some variables such as reaction time, salinity, sample volume and headspace volume. SPME-GC-MS and SPME-GC-FID techniques were compared; quality assurance parameters such as sensitivity, selectivity and precision were established. The proposed procedure showed limits of detection between 0.025 and 1 ng/L. The linearity was in the 0.025-5000 ng/L range. The precision expressed as relative stan…
VALUTAZIONE DI DUE TEST IMMUNOCROMATOGRAFICI PER LA DIAGNOSI DI INFEZIONE DA ROTAVIRUS
2017
Obiettivo dello studio: Valutare l’efficienza diagnostica di due tecniche immunocromatografiche (IC) utilizzate per la ricerca di antigeni di Rotavirus di gruppo A (RVA) nei campioni fecali: CerTest Rotavirus+Adenovirus (Biotec) e Vikia Rota+Adeno (bioMérieux). relazione Entrambe le tecniche IC sono state confrontate con la PCR RealTime, considerata il gold standard per la diagnosi delle enteriti da RVA. I RVA sono i principali agenti eziologici di gastroenterite acuta (AGE) nei bambini al di sotto dei 5 anni di età, con elevati tassi di morbilità e mortalità nelle diverse aree geografiche. Metodi impiegati: Uno studio retrospettivo è stato eseguito su 2096 campioni fecali, raccolti dal 200…
A preliminary study in Wistar rats with enniatin : A contaminated feed
2014
A 28-day repeated dose preliminary assay, using enniatin A naturally contaminated feed through microbial fermentation by a Fusarium tricinctum strain, was carried out employing two months-old female Wistar rats as in vivo experimental model. In order to simulate a physiological test of a toxic compound naturally produced by fungi, five treated animals were fed during twenty-eight days with fermented feed. As control group, five rats were fed with standard feed. At the 28th day, blood samples were collected for biochemical analysis and the gastrointestinal tract, liver and kidneys were removed from each rat for enniatin A detection and quantitation. Digesta were collected from stomach, duode…
Un protocollo scientifico per la desalinizzazione di materiali lapidei: caso studio dei mosaici della Villa del Casale (Sicilia)
2009
Desarrollo de nuevas estrategias analíticas basadas en la espectrometría de masas para la determinación de contaminantes procedentes de la migración …
2019
Esta Tesis Doctoral tiene como objetivo principal el desarrollo de nuevas metodologías analíticas adecuadas para el análisis de contaminantes orgánicos procedentes de los materiales destinados a entrar en contacto con los alimentos, mediante la utilización de la cromatografía líquida acoplada a la espectrometría de masas. Además, se ha utilizado la biomonitorización humana para evaluar la exposición y el riesgo de una población de mujeres lactantes a distintos contaminantes procedentes de envases plásticos.En la introducción de la tesis se ha realizado una revisión crítica del estado actual de las metodologías analíticas para la determinación de contaminantes derivados de los materiales. Lo…
One-Year Changes in Urinary Microbial Phenolic Metabolites and the Risk of Type 2 Diabetes—A Case-Control Study
2022
The intake of polyphenols has been associated with a risk reduction of type 2 diabetes. Nevertheless, to the best of our knowledge, the molecules that might be metabolically active after ingestion are only starting to be investigated regarding this metabolic disease. To investigate the association between one-year changes in urinary microbial phenolic metabolites (MPM) and the incidence of type 2 diabetes, we performed a case-control study using data and samples of the PREDIMED trial including 46 incident type 2 diabetes cases of 172 randomly selected participants. Eight urinary MPMs were quantified in urine by liquid chromatography coupled to mass spectrometry and used to assess their asso…
The Role of Covalent Functionalization in the Thermal Stability and Decomposition of Hybrid Layered Hydroxides
2020
The room temperature synthesis of two Co-based hybrid layered hydroxides containing the same organic ligand (suberate [Sub]), one connected through purely electrostatic interactions (CoAl layered double hydroxide [LDH]), and the other covalently functionalized (α-CoII simonkolleite phase) has been carried out. The magnetic properties exhibit an acute difference in the magnetization temperatures (from ≈10 K for the CoAl-LDH to ≈55 K for the α-CoII). Moreover, the role of the covalent functionalization in the thermal stability and the decomposition has been investigated by a forefront characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spect…