Comparison of two synthesis methods on the preparation of Fe, N-Co-doped TiO2 materials for degradation of pharmaceutical compounds under visible light

"In this work, we report the synthesis, characterization and photocatalytic evaluation of visible light active iron-nitrogen co-doped titanium dioxide (Fe3+-TiO2?xNx) nanostructured catalyst. Fe3+-TiO2?xNx was synthesized using two different chemical approaches: sol-gel (SG) and microwave (MW) methods. The materials were fully characterized using several techniques (SEM, UV–Vis diffuse reflectance DRS, X-ray diffraction XRD, and X-ray photoelectron spectroscopy XPS). The photocatalytic activity of the nanostructured materials synthesized by both methods was evaluated for the degradation of amoxicillin (AMX), streptomycin (STR) and diclofenac (DCF) in aqueous solution. Higher degradation efficiencies were encountered for the materials synthesized by the SG method, for instance, degradation efficiencies values of 58.61% (SG) and 46.12% (MW) were observed for AMX after 240 min of photocatalytic treatment under visible light at pH 3.5. With STR the following results removal efficiencies were obtained: 49.67% (SG) and 39.90% (MW) at pH 8. It was observed the increasing of degradation efficiencies values at longer treatment periods, i.e., after 300 min of photocatalytic treatment under visible light, AMX had a degradation efficiency value of 69.15% (MW) at pH 3.5, DCF 72.3% (MW) at pH 5, and STR 58.49% (MW) at pH 8.

Funciones de Pdé para la modelación de datos de adsorción

En este estudio se describe la aplicación de funciones de Padé en la modelación de datos cinéticos y de equilibrio de adsorción. Especificamente, se realiza un comparativo del proceso de ajuste de datos usando este tipo de funciones racionales y modelos clásicos del área. Como caso de estudio, se analiza la adsorción de cadmio en solucion acuosa empleando carbón de hueso. Los resultados obtenidos indican que las funciones de Padé son modelos alternativos y flexibles para mejorar los resultados del proceso de correlación de datos de adsorción

Biodiesel, un combustible renovable

The substitution of traditional petroleum-based diesel fuel for others of biological nature, represents nowadays one of the greatest scientific challenges. Biodiesel is a renewable fuel derived from vegetable oils (edibles or non edibles; new or used) with similar properties to petroleum-based diesel fuel. Besides, it has significantly lower emissions of carbon monoxide, sulfur, aromatic hydrocarbons and particulate matter. The most common way to produce biodiesel is by transesterification of vegetable oils with methanol and homogeneous basic catalysis. A technological and economic assessment on the fundamentals of biodiesel production from vegetable oils, animal fats or used vegetable oils is presented in this work.La sustitución de los combustibles denominados fósiles o tradicionales, derivados del petróleo, por otros, de origen biológico, representa uno de los grandes retos que enfrenta la humanidad actualmente. Una de las alternativas más factibles para reemplazar el diesel de petróleo es la producción de biodiesel. É ste es un combustible renovable derivado de aceites vegetales (comestibles o no comestibles; nuevos o usados) y grasas animales que posee propiedades similares a las del petróleo. Además, se ha encontrado que con el uso de biodiesel se logran reducir las emisiones de monóxido de carbono, azufre, hidrocarburos aromáticos y partículas sólidas. La manera convencional de sintetizar biodiesel es mediante la transesterificación de aceites vegetales con metanol y catálisis homogénea básica. El presente trabajo describe los fundamentos de la producción de biodiesel sintetizado a partir de aceites vegetales, grasas animales o aceites de reúso, además del análisis de la factibilidad técnica y económica de la producción del mismo

Desarrollo de un método inmuno blot para detectar glucomacropéptido (GMP) como índice de adulteración de leche de vaca con suero de quesería

Milk is a product of high nutritional value and is considered commodity product for human consumption, which is why the dairy sector is of great socio-economic importance. Worldwidemilk processor industries and distributors have problems of milk adulteration with cheese whey. Most used method to detect cheese whey is the identification of a glycomacropeptide (GMP), which is present only in the cheese whey but not in milk. At present, methods to detect GMP require major work and time, presenting problems of sensitivity and accuracy at low concentrations. We developed a novel western blot analysis for GMP detection, using anti-GMP polyclonal antibodies. This assay can detect GMP with greater sensitivity, precision and speed that the methods used so far.La leche es un producto que contiene un alto valor nutricional y es considerada como un producto básico en la alimentación humana, razón por la cual, el sector lechero tiene gran importancia socioeconómica a nivel mundial. Las industrias procesadoras y comercializadoras de leche tienen problemas con su adulteración ocasionado por el suero de queserías. Uno de los métodos más usados para detectarlo es a través de la identificación de un glucomacropéptido (GMP), presente sólo en el suero de quesería y no en la leche. Los métodos para detectar GMP requieren de mucho trabajo y tiempo, y, a su vez, presentan problemas de sensibilidad y precisión en concentraciones bajas. En esta investigación se desarrolló un nuevo método de análisis mediante inmuno blot para la detección de GMP, usando anticuerpos policlonales anti-GMP. De este modo, puede detectarse GMP con una mayor sensibilidad, precisión y rapidez que con los métodos utilizados hasta ahora

Phytochemical Profiling of <i>Coryphantha macromeris</i> (Cactaceae) Growing in Greenhouse Conditions Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

Chromatographic separation combined with mass spectrometry is a powerful tool for the characterization of plant metabolites because of its high sensitivity and selectivity. In this work, the phytochemical profile of aerial and radicular parts of Coryphantha macromeris (Engelm.) Britton &amp; Rose growing under greenhouse conditions was qualitatively investigated for the first time by means of modern ultra-high-performance liquid chromatography&#8315;tandem mass spectrometry (UHPLC-PDA-HESI-Orbitrap-MS/MS). The UHPLC-PDA-HESI-Orbitrap-MS/MS analysis indicated a high complexity in phenolic metabolites. In our investigation, 69 compounds were detected and 60 of them were identified. Among detected compounds, several phenolic acids, phenolic glycosides, and organic acids were found. Within this diversity, 26 metabolites were exclusively detected in the aerial part, and 19 in the roots. Twenty-four metabolites occurred in both plant parts. According to the relative abundance of peaks in the chromatogram, ferulic and piscidic acids and their derivatives may correspond to one of the main phenolic compounds of C. macromeris. Our results contribute to the phytochemical knowledge regarding C. macromeris and its potential applications in the pharmaceutical and cosmetic industries. Besides, some metabolites and their fragmentation patterns are reported here for the first time for cacti species