Abstract. Red wine is distinguished by a high economic and cultural value and therefore, its reliable characterization is important to assess its quality and authentication. Currently, Mexican wine consumption is growing due to wine tourism initiatives, then the determination of the chemical profile of commercial selected samples of young and aged red wines produced at wineries from Queretaro and Aguascalientes was performed. Seventy-eight nonvolatile compounds were identified by ultra performance liquid chromatography coupled to mass spectrometry. Three main families of secondary metabolites (Flavonols, ellagitannins and anthocyanins) were quantified by differential pulse voltammetry using carbon screen printed electrodes (SPEs). Tempranillo aged wine from Vinos del Marqués, Queretaro, showed the highest content of total polyphenols and anthocyanins from the evaluated wine samples. This research contributes to the knowledge of the chemical profile of commercial selected samples from wineries that belong to Mexican wine routes in a consolidated and experimental stage.

Resumen. El vino tinto se distingue por un alto valor económico y cultural y, por lo tanto, su caracterización confiable es importante para evaluar su calidad y autenticación. Actualmente, el consumo de vinos mexicanos se encuentra en crecimiento debido a las iniciativas de enoturismo, por ello, se llevó a cabo la determinación del perfil químico de muestras comerciales seleccionadas de vinos tintos jóvenes y de conserva producidos en bodegas de Querétaro y Aguascalientes. Se identificaron setenta y ocho compuestos no volátiles mediante cromatografía líquida de alta resolución acoplada a espectrometría de masas. Tres familias principales de metabolitos secundarios (flavonoles, elagitaninos y antocianinas) fueron cuantificadas mediante voltamperometría de pulso diferencial utilizando electrodos serigrafiados (SPEs) de carbón. El vino Tempranillo conserva de Vinos del Marqués, Querétaro, mostró el mayor contenido de polifenoles totales y antocianinas de las muestras de vino evaluadas. Esta investigación contribuye al conocimiento del perfil químico de muestras comerciales seleccionadas de bodegas pertenecientes a las rutas del vino mexicano en etapa consolidada y experimental.

Bimetallic nanoparticles are of special interest for their potential applications for fuel cells, mainly for portable power applications. Among the bimetallic systems, Pt-Pd bimetallic nanoparticles have received great interest as they can be widely used as effective catalysts for various electrochemical reactions. In this work, Pt-Pd alloy bimetallic nanoparticles were synthesized through a chemical reduction method. The nanoparticles were characterized using aberration-corrected scanning/transmission electron microscopy (STEM). Also, parallel beam X-Ray diffraction analysis was carried out to evaluate the crystallographic structure. High-angle annular dark field (HAADF)-STEM images of the Pt-Pd bimetallic nanoparticles were obtained. The contrast of the images shows that the nanoparticles have an alloy structure with an average size of 7.15 nm. To understand the properties of the bimetallic nanoparticles, it is necessary to know the distribution of the elements in the nanostructure. We have used a semi-quantitative method to analyze the HAADF-STEM images, which allowed us to measure the total intensity of the scattered electrons for each atomic column. HAADF-STEM images of the Pt-Pd bimetallic nanoparticles were compared directly with image simulations, good agreement between simulation and experimental images was found. Cyclic voltammetry studies were carried out to analyze the electrochemical behavior of the bimetallic nanoparticles.