RESUMO
In Chile, limited information is available on colorants in commonly consumed foods among vulnerable age groups. We developed and validated a rapid HPLC-DAD method to simultaneously evaluate 11 synthetic colorants in candies, beverages, ice cream, and cereals. The method exhibited excellent analytical performance for all 11 colorants with LOD (0.44 - 1.55 mgL-1), LOQ v(1.32 - 4.70 mgL-1), precision (4.0 and 7.3% RSD), and recovery (80 - 105%) in fortified matrices (10-50-100 mgL-1). The highest detection frequencies were as follows: cereals > candies > beverages > ice cream. Sunset Yellow was the most prevalent colorant in all food matrices, followed by Allura Red and Azorubine. Positive samples contained between 1 and 5 synthetic colorants. With the exception of cereals, the colorant concentrations in the remaining matrices exceeded the Codex Alimentarius regulations and the values reported in other studies worldwide, indicating the Chilean population is at risk.
Assuntos
Corantes de Alimentos , Cromatografia Líquida de Alta Pressão , Chile , Corantes de Alimentos/análise , Grão Comestível/química , Bebidas/análise , Doces/análise , Sorvetes/análise , Contaminação de Alimentos/análiseRESUMO
The study conducted in the state of Colima, western Mexico, aimed to assess the 1) occurrence, 2) temporal variability, 3) spatial variability, and 4) potential risk for honeybees and human consumption of pesticide-contaminated honey. For that purpose, 48 pesticides were determined in bees and their honey during both dry and wet seasons. The research considered two variables: land use categorization (irrigated agriculture, rainfed agriculture, grassland, and forest area) and location (coastal, valley, and mountain). Bee and honey samples were collected, pre-treated using solid-phase extraction (SPE), and analyzed using LC-MS/MS and GC-MS techniques. Occurrence: of the total number of pesticides, 17 were detected in the bee samples and 12 in the honey samples. The pesticides with the highest concentrations in the bee samples were glufosinate ammonium, picloram, and permethrin, while in the honey samples, picloram, permethrin, and atrazine were the most prevalent. Temporal variability: analyses revealed significant differences between dry and wet seasons for glufosinate ammonium and DEET in bee samples and only for glufosinate ammonium in honey samples. Spatial variability: analyses showed a trend in the number of detected pesticides, with irrigated agriculture areas having the highest detection and grassland areas having the least. The human potential risk assessment of contaminated honey consumption indicated no risk. The bee's potential risk for consumption of pesticides contaminated honey revealed chronic effects due to permethrin in a general scenario, and carbofuran, diazinon and permethrin in the worst scenario, and potential risk of acute effects by permethrin. The findings of this study contribute to understanding the contamination levels of pesticides in bees and their honey, emphasizing the importance of monitoring and mitigating the adverse effects of pesticide exposure on bee populations and environmental health.
Assuntos
Monitoramento Ambiental , Mel , Praguicidas , Abelhas , Mel/análise , Animais , Medição de Risco , México , Praguicidas/análise , Análise Espaço-Temporal , Estações do Ano , Contaminação de Alimentos/análise , HumanosRESUMO
The progressive influx of engineered nanoparticles (ENPs) into the soil matrix catalyses a fundamental transformation in the equilibrium dynamics between the soil and the edaphic solution. This all-encompassing investigation is geared towards unravelling the implications of an array of ENP types, diverse dosages and varying incubation durations on the kinetics governing Cd2+ sorption within Ultisol soils. These soils have been subjected to detailed characterizations probing their textural and physicochemical attributes in conjunction with an exhaustive exploration of ENP composition, structure and morphology. To decipher the intricate nuances of kinetics, discrete segments of Ultisol soils were subjected to isolated systems involving ENP dosages of 20 and 500 mg ENPs·kg-1 (AgNPs, CuNPs and FeNPs) across intervals of 1, 3 and 6 months. The comprehensive kinetic parameters were unveiled by applying the pseudo-first-order and pseudo-second-order models. At the same time, the underlying sorption mechanisms were studied via the intra-particle diffusion model. This study underscores the substantial impact of this substrate on the kinetic behaviours of contaminants such as Cd, emphasizing the need for its consideration in soil-linked economic activities and regulatory frameworks to optimize resource management.
RESUMO
Perchlorate and chlorate are endocrine disruptors considered emerging contaminants (ECs). Both oxyanions are commonly associated with anthropogenic contamination from fertilizers, pesticides, explosives, and disinfection byproducts. However, the soils of the Atacama Desert are the most extensive natural reservoirs of perchlorate in the world, compromising drinking water sources in northern Chile. Field campaigns were carried (2014-2018) to assess the presence of these ECs in the water supply networks of twelve Chilean cities. Additionally, the occurrence of perchlorate, chlorate and other anions typically observed in drinking water matrices of the Atacama Desert (i.e., nitrate, chloride, sulfate) was evaluated using a Spearman correlation analysis to determine predictors for perchlorate and chlorate. High concentrations of perchlorate (up to 114.48 µg L-1) and chlorate (up to 9650 µg L-1) were found in three northern cities. Spatial heterogeneities were observed in the physicochemical properties and anion concentrations of the water supply network. Spearman correlation analysis indicated that nitrate, chloride, and sulfate were not useful predictors for the presence of perchlorate and chlorate in drinking water in Chile. Hence, this study highlights the need to establish systematic monitoring, regulation, and treatment for these EC of drinking water sources in northern Chilean cities for public health protection.
Assuntos
Água Potável , Poluentes Químicos da Água , Água Potável/química , Cloratos/análise , Chile , Nitratos/análise , Percloratos , Cidades , Cloretos/análise , Poluentes Químicos da Água/análiseRESUMO
A novel hybrid nanomaterial, nanoscale zero-valent iron (nZVI)-grafted imogolite nanotubes (Imo), was synthesized via a fast and straightforward chemical procedure. The as-obtained nanomaterial (Imo-nZVI) was characterized using transmission electron microscopy (TEM), electrophoretic mobility (EM), and vibrating sample magnetometry (VSM). The prepared Imo-nZVI was superparamagnetic at room temperature and could be easily separated by an external magnetic field. Sorption batch experiments were performed for single- and multicomponent systems and demonstrated that Hg2+ and Pb2+ could be quantitatively adsorbed at pH 3.0. For multicomponent systems, maximum adsorption capacities of 61.6 mg·g-1 and 76.9 mg·g-1 were obtained for Hg2+ and Pb2+ respectively. It was observed that the functional groups in Imo-nZVI interact preferentially with analytes according to the Misono softness parameter. The higher performance of Imo-nZVI compared with Imo and nZVI is related to the increased number of adsorption sites in the functionalized nanomaterial. The sorption equilibrium data obeyed the Langmuir model, while kinetic studies demonstrated that the sorption processes of Hg2+ and Pb2+ followed the pseudo-second-order model. This study suggests that the Imo-nZVI composite can be used as a promising sorbent to provide a simple and fast separation method to remove Hg and Pb ions from contaminated water.
Assuntos
Mercúrio , Poluentes Químicos da Água , Adsorção , Ferro/química , Cinética , Chumbo , Poluentes Químicos da Água/análiseRESUMO
Here, we announce the draft genome sequence of Pseudomonas sp. strain AN3A02, isolated from the rhizosphere of one of the only two species of vascular plants existing in the Antarctic continent, Deschampsia antarctica Desv. This isolate, which inhibited the mycelial growth of Botrytis cinerea in dual culture, has a genome sequence of 6,778,644 bp, with a G+C content of 60.4%. These draft genome sequence data provide insight into the genetics underpinning the antifungal activity of this strain.
RESUMO
Some artificial sweeteners (ASs) are used in pig feeds, although little is known on this regard. An investigation was conducted by determining seven common ASs in pig feed, manure, wastewater, compost, and soil from 16 pig farms in Tianjin, China. Saccharin (SAC) was predominant in feed (1.41-326 mg/kg) and manure samples (1.06-401 mg/kg). The annual mass loads of ASs in pig feeds were estimated at 5.69-119, 4.92-149, and 1.29-35 kg per 103 piglets, hogs, and sows, respectively. The annual emission of ASs via biowaste (i.e., manure) was estimated at 3.58-85.2, 0.04-26.2, and 0.08-9.97 kg per 103 capita for the three dominant ASs, i.e., SAC, neotame (NEO), and cyclamate (CYC). On a global scale, SAC was also widely detected at concentrations of 0.01-326 mg/kg in pig feed from China, Switzerland, Japan, Chile, and the United States, suggesting the worldwide use of ASs in pig feed. NEO and CYC were found in 41% and 30% of the feed samples, respectively, at concentrations of 0.05-70 mg/kg, whereas other ASs were barely found with rather lower concentrations. The annual mass loads of ASs consumed via pig feed consumption were estimated at 2400 tons worldwide. Thus, pig farming is an important source of ASs to the environment.
Assuntos
Esterco , Edulcorantes , Animais , Chile , China , Fazendas , Feminino , Japão , Inquéritos e Questionários , Suínos , SuíçaRESUMO
The interest in and demand for natural dyes has increased significantly in recent years; however, very few natural blue dyes are commercially available, because blue colored compounds in nature are relatively rare. In this study, a blue pigment-producing bacteria from Lake Chungará (Atacama Desert, Chile) was isolated, and its blue pigment was purified and chemically characterized. The pigment-producing strain was identified as Pseudarthrobacter sp. by 16S rRNA gene sequencing. The pigment was separated from the filtered culture medium by column chromatography/solid-phase extraction using different resins (ionic exchange, C-18, size exclusion). The strain produced up to 2.5 g L-1 of blue pigment, which was very soluble in water, partially soluble in methanol and insoluble in other organic solvents. The pigment was analyzed and characterized by analytical HPLC, UV-Vis, FT-IR, and H-NMR, and purified by semi-preparative HPLC. The pigment was non-toxic to brine shrimp (LD50 > 2.3 g L-1) and was stable at pH 6-10 at temperatures below 60 °C. HPLC analysis shows that the pigment is composed of four major blue fractions. The physicochemical properties and structural analysis demonstrate that this pigment belongs to the indochrome isomers, whose properties have yet to have been characterized. The high solubility in water, good stability in neutral and basic pH, and negligible toxicity of the blue pigment make it a good candidate suitable for several industrial and possibly some food applications.
Assuntos
Micrococcaceae/química , Pigmentos Biológicos/biossíntese , Animais , Artemia , Chile , Cromatografia Líquida de Alta Pressão , Cor , Meios de Cultura , Clima Desértico , Espectroscopia de Ressonância Magnética , Micrococcaceae/classificação , Micrococcaceae/isolamento & purificação , Pigmentos Biológicos/isolamento & purificação , RNA Ribossômico 16S/genética , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Testes de Toxicidade AgudaRESUMO
Introducción: Las brechas en salud se incrementan entre las zonas urbana y rural. Y es necesario intervenciones que promuevan la atención integral, así como mejorar la infraestructura y equipamiento en los establecimientos de salud (EESS). Objetivo: Valorar la intervención de la Segunda Fase del Programa de Apoyo a la Reforma del Sector Salud (PARSALUD II) sobre indicadores de proceso de salud materna. Material y métodos: Se realizó estudio descriptivo longitudinal comparativo. Se comparó 07 indicadores de proceso de salud materno, al inicio y final del periodo del 2008 2013. Resultados: Se estudió a 66 EESS de 09 departamentos del Perú, los indicadores con cambios significativos en nivel de atención I, fueron: la cobertura de suplemento de sulfato ferroso de 23,85% ± 8,42 a 54,56 ± 14,38; la cobertura de corticoide por parto prematuro de 74,48% ± 40,69 a 84,35% ± 24,89; y en el nivel de atención II, fueron: el porcentaje de partos por cesárea del 8,04% ± 4,74 en el periodo inicial hasta 24,35% ±8,70, el indicador de uso de sulfato de magnesio en casos de hipertensión inducida por la gestación (HIG) de 27,8% ± 32,45 a 29,8% ± 31,78 al final del periodo. Conclusiones: los establecimientos de salud del ámbito del PARSALUD II, tuvieron un efecto importante sobre los indicadores del proceso de salud de la madre.
RESUMO
Various studies have evaluated the accumulation of ClO4(-) in lettuce (Lactuca sativa), but very few have dealt with the variables that can interfere with its capture. The present study evaluates the transfer of ClO4(-) in two L. sativa varieties: butter head (L. sativa var. capitata) and cos lettuce (L. sativa var. crispa) under hydroponic conditions. The ClO4(-) concentrations used correspond to levels (1 and 2mgL(-1)), measured in irrigation water in the Iquique region in the north of Chile. Results indicate that the capture of ClO4(-) is dependent on its concentration, lettuce genotype, and temperature. The butter head variety accumulates the highest perchlorate concentrations. Anion competition involving NO3(-) (16 and 48mM), Cl(-) (23 and 56mM), and SO4(2-) (10 and 20mM) was evaluated, being NO3(-) (48mM), the most significant competition reducing the concentration of ClO4(-) in tissues of L. sativa varieties.
Assuntos
Lactuca/química , Lactuca/genética , Percloratos/química , Temperatura , Ânions/química , Chile , Genótipo , Lactuca/metabolismo , Percloratos/análise , Folhas de Planta/química , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismoRESUMO
Contiene: Avances logrados en lo que atañe a la Educacion Intercultural y Bilingue (EIB) en Bolivia - Principales experiencias y propuestas sobre educacion intercultural y bilingue desarrolladas y planteadas - Principales elementos conceptuales sobre educacion intercultural y bilingue: una perspectiva sociolinguistica - Bilinguismo radical: una aproximacion guarani - Diversidad cutural y procesos pedagogicos, lineamientos para una propuesta de educacion intercultural en escuelas urbano-populares de la region andina de Bolivia - Educacion intercultural y bilingue: una aproximacion Katarista - Hacia una interculturaidad activa.
RESUMO
Contenido:2.-Antecedentes, definicion del hormigon, analisis actual de la construccion 3.-Importancia del estudio, objetivo general, objetivos especificos 4.-Materiales componentes del hormigon, cementos,agua, arena, grava, aditivos 5.-Propiedades que afectan la calidad del hormigon, relacion agua cemento, relacion cemento agregados, material que pasa el tamiz No200, forma de los aridos, textura superficial de los aridos, granulometria de los aridos, durabilidad de los aridos, absorcion de los aridos, contenido organico, equivalente arena, ataque quimico, ciclos hielo deshielo, calor de hidratacion, reaccion alcali agregado, trabajabilidad del hormigon, curado del hormigon 6.-Metodo de Faury para dosificacion de hormigones, determinacion del tamaño maximo, determinacion de la fluidez, determinacion de la consistencia, determinacion de la relacion agua cemento, determinacion de la dosificacion 7.-Ensayos de agregados mas usados en la ciudad de La Paz, material que pasa el tamiz No200, ensayos de forma, contenido deterrones de arcilla, ensayos de granulometria, desgaste de los angeles 8.-Dosificaciones para las mezclas de prueba, dosificaciones con cemento viacha especial y aridos tecnocret 9.-Mezclas de prueba, asentamiento 10.-Resultados de las pruebas de compresion 11.-Determinacion de los factores para el metodo, cono de Abrams 12.-Dosificacion version Boliviana Faury, metodo general, metodo simplificado13.-Aplicacion practica para el arido mas aconsejable 14.-Recomendaciones en el uso del hormigon 15.-Conclusiones.
RESUMO
Al haberse descubierto en el territorio nacional varias zonas radioactivas, las cuales presentan minerales con apreciable contenido de uranio, resulto muy interesante iniciar el estudio básico para el tratamiento de estos minerales. El objetivo de este trabajo es primordialmente, coadyuvar a la evaluación de las reservas de minerales que la Comisión de Energía Nuvclear está efectuando, conociendo parámetros que conduzcan a la determinación de la factibilidad técnica, para la obtención de concentrados comerciables. El trabajo comprende un estudio comparativo de diferentes técnicas de lixiviación aplicadas al mineral de la zona de Cotaje, ubicada en la provincia Quijarro del Departamento de Potosí. Un estudio básico de procesamiento de minerales uraníferos por métodos hidrometalúrgico, tiene en la etapa de lixiviación, uno de sus puntos más importantes, ya que ella fija practicamente el rendimiento del proceso y representa la mayor contribución a los costos de tratamiento. En la tecnología de la concentración hidrometalúrgica de los minerales de uranio, la lixiviación se puede clasificar desde el punto de vista químico, en dos clases de importancia industrial: ácida y alcalina. La comparación para un mineral, de las condiciones de lixiviación en ambos medios, tiene particular significación si a lo dicho anteriormente se agrega que el medio en que se realiza la lixiviación afecta a todo el "flow-sheet".