Pregrado Química Ambiental

URI permanente para esta colecciónhttp://hdl.handle.net/11634/229

Examinar

Mostrando 1 - 20 de 138

Desarrollo, caracterización y evaluación biológica de sistemas nanoestructurados derivados del aceite esencial del clavo de olor (Syzygium aromaticum)
(Universidad Santo Tomás, 2026-04-30) Jiménez Gómez, Carol Tatiana; Ramírez Rojas, Heilyn Tatiana; Cervantes Díaz, Martha; Herrera Sandoval, Laura Viviana; Leal Pinto, Sandra Milena; Rueda Wandurraga, Verónica Lucía; Bastidas Duarte, Sergio Esteban; Universidad Santo Tomás
Problem: the development of plant-based nanomaterials under sustainable approaches requires green synthesis strategies and comprehensive assessments to determine how nanostructuring modifies natural matrices. In the case of Syzygium aromaticum essential oil and eugenol, studies integrating extraction, characterization, nanostructuring, and biological evaluation within a single experimental design remain limited. Objective: to develop and characterize nanostructured systems derived from clove essential oil and eugenol, and to analyze their influence on physicochemical and biological properties. Method: essential oil was obtained by microwaveassisted hydrodistillation and characterized by GC-MS. Eugenol was isolated by acid-base extraction. Both precursors were evaluated through acidity index, peroxide index, refractive index, and relative density. Silver nanoparticles were then synthesized by a green route, and eugenol O/W nanoemulsions were prepared by spontaneous emulsification. The systems were characterized by UV-Vis, DLS, and SEM, and evaluated through ABTS•+ and phytotoxicity assays using Lactuca sativa. Results and discussion: the essential oil yield was 9.6% and its composition was dominated by eugenol (67.9%), trans-β-caryophyllene (16.8%), eugenyl acetate (5.1%), and α-humulene (2.4%). Isolated eugenol reached 90.9% purity. Physicochemical properties indicated stability of both the essential oil and eugenol. AgNPs showed sizes between 37.87 and 62.92 nm, whereas nanoemulsions ranged from 11.45 to 30.44 nm, with low polydispersity and colloidal stability. NE-2 and NE-3 exhibited higher antioxidant activity than essential oil and the lowest IC50 values, demonstrating that eugenol nanostructuring significantly enhanced the biological response in Lactuca sativa under the evaluated experimental conditions.
Evaluación de la calidad del aire en zonas cercanas al Valle de Aburra/Antioquia, Colombia por contaminantes atmosféricos con influencia minera e industrial.
(Universidad Santo Tomás, 2026-03-02) Sánchez Gerena, Ricardo Andrés; Rozo Correa, Ciro Eduardo; Universidad Santo Tomás
The present study aims to evaluate air quality in an area near a mining activity zone in the department of Antioquia by analyzing the criteria pollutants (NO₂, SO₂, O₃, PM10, and PM2.5) and their relationship with meteorological conditions through the calculation of the Air Quality Index (AQI). To achieve this, a comparative analysis was conducted between the years 2022 and 2023 using data obtained from monitoring stations. The concentrations of criteria pollutants and their temporal variability were characterized, identifying the meteorological factors that influence their dispersion and accumulation. Additionally, AQI values were calculated for each pollutant to determine their impact on air quality and public health. Furthermore, pollution roses were generated to assess the influence of wind direction and speed on the distribution of pollutants in the study area. The results indicated that there were no exceedances for any of the pollutants evaluated according to current regulations. However, ozone (O₃) showed concentrations close to the regulatory threshold, particularly at station CA-1 during 2023. In the AQI calculation, most stations remained in a good category for health, indicating favorable air quality conditions in the study area. This analysis provides key information for environmental management and the development of mitigation strategies aimed at improving air quality in the region.
Implementación y validación del método de ensayo para la cuantificación de aceite en ceras de refinería por cromatografía de gases (GC)
(Universidad Santo Tomás, 2026-02-25) Bueno Cano, Azelleb Jaylene; Osorio Martinez, Carlos Alberto; Rodriguez Sandoval, Alexis; Villalba, Arbey Alexander; Universidad Santo Tomas
The purpose of this study is to implement and validate the gas chromatography (GC) testing method as an alternative to the traditional method for quantifying oil in refinery waxes, seeking to optimize analysis times, reduce sample handling, and improve analyst safety. Problem: The ASTM D721 gravimetric method used in the laboratory is a slow and operationally demanding procedure, involving high sample handling, exposure to hazardous solvents, and critical operating conditions, which negatively impacts laboratory productivity and contributes to variability in results. Objective: To implement and validate a gas chromatography method for the quantification of oil in refinery waxes, applied to real matrices and under laboratory operating conditions. Method: A GC test method was developed and implemented, establishing the chromatographic conditions and evaluating analytical parameters such as repeatability, precision, and comparison with the ASTM D721 reference method, in order to ensure the reliability of the results obtained. Results: The implemented method was applied to production waxes from the Barrancabermeja Refinery Management (GRB), showing consistent results, good agreement with the gravimetric method, and a significant improvement in operational ease and analysis efficiency. As a result of the study, the method was presented to the refinery's General Management, accompanied by technical instructions and knowledge transfer through training of the paraffin station personnel.
Síntesis de Pirazoles e Isoxazoles Obtenidos de Derivados Curcuminoides y Predicción del Metabolismo empleando herramientas computacionales
(Universidad Santo Tomás, 2025-09-18) Martínez Gelves, Juan Esteban; Osorio Martínez, Carlos Alberto; Castañeda Trujillo, Lady Diana
In recent scientific advances, various alternatives have been found for the production of complexes that exhibit biological activity (antifungal and antibacterial). Due to the complexity of finding a 100% effective solution, methodologies have been proposed to demonstrate effectiveness in treating bacteria, fungi, and other biological factors. As an alternative to the aforementioned, we have proposed research and methodologies for the synthesis of curcuminoid complexes, to subsequently conduct in silico tests using various computational software and determine their possible effectiveness for the development of future biological tests employing this type of compounds. It has been demonstrated thru various studies that curcuminoid complexes incorporating O-N (isoxazole) and N-H (pyrazole) groups exhibit high antibacterial and antifungal activity. With this research work, the aim is to initiate the study of the pharmacokinetics of these new molecules using various software and simulators that can predict the characteristics of lipophilicity and/or solubility in water, as well as their metabolism and permeation in relevant physiological membranes such as the blood-brain barrier, hepatic, endocrine, pulmonary, among others. Understanding this information thru the analysis of in silico studies will facilitate the identification of certain relevant functional groups in the molecules under study, to take them into account in future research and prevent the formation of potential highly toxic reactive metabolites. In the following work, the synthesis process for obtaining curcumin derivatives is shown, followed by the formation of their corresponding isoxazole and pyrazole complexes, their physical and chemical characterization, and based on in silico studies, determine how these compounds are metabolized in the body in case they are administered orally. The aim is to understand these new molecules; their pharmacokinetic behavior and identify the ADME (Absorption, Distribution, Metabolism, Excretion) processes they would undergo if used as drugs, and determine their possible adverse and/or toxic effects using predictive software. Similarly, in order to measure the toxicity of the compounds to be synthesized, toxicological tests will be conducted using lettuce seeds (Lactuca sativa).
Nuevos sensores fluorescentes basados en triazina-aminoácidos para la detección de metales pesados en solución
(Universidad Santo Tomás, 2025-04-24) Sánchez Becerra, Lina Marcela; Osorio Martínez, Carlos Alberto; Alvarado Rueda, Lizeth Johanna
At present, heavy metal contamination is a major environmental problem that causes serious damage to the environment, both biotic and abiotic. It is one of the great barriers to overcome to achieve a sustainable industrial development in the medium and long term, since these materials are used in underdeveloped countries without major restrictions for the manufacture of parts, chemical compounds, defense weapons, among other diverse uses. This generates health problems such as respiratory diseases, congenital diseases due to continuous exposure, among others. It is for these reasons that agencies for the protection and conservation of the environment carry out continuous monitoring and determine regulations for the use and disposal of these substances. However, monitoring methods for heavy metals are time-consuming and some have limitations in sampling techniques and subsequent analysis, which is why there is a great demand to develop faster, simpler, more reliable methods that allow in situ analysis of the sample for the detection of heavy metals. The specific property for which 2,4,6-trichloro-1,3,5-triazine (cyanuric chloride) is used is the capacity to undergo an aromatic nucleophilic substitution reaction (SNAr) under controlled temperature conditions and the addition of the ligands has a specific order. This project involves the preparation of triazine analogues molecular sensors with amino acids as ligands (valine, glycine, phenylalanine) in order to achieve the detection of heavy metals in aqueous solutions through changes in the absorption-emission process of the complex formed and the observation of fluorescence or colorimetric changes in the samples.
Caracterización fisicoquímica de un bio-concreto a partir de la adición de residuos agroindustriales: cascara de huevo y cascarilla de arroz
(Universidad Santo Tomás, 2025-03-07) Maldonado Vargas, Angie Juliana; Rozo Correa, Ciro Eduardo; Universidad Santo Tomás
The construction sector, although it has guaranteed a better quality of life, is classified as one of the main sources of pollution, both directly and indirectly; the manufacturing of aggregates such as cement and sand gives rise to innumerable environmental problems. On the other hand, in the rice and poultry agro-industrial sector, the incorrect disposal of waste generates negative impacts on the environment: in the rice industry, the rice production process generates rice husk waste and its high demand contaminates the soil; Its open burning generates greenhouse gases as does the poultry industry in egg production. Thanks to the needs of climate change, this research sought to take advantage of the composition of agro-industrial waste (egg shells and rice husks) as replacements for cement and sand in the concrete manufacturing process. Based on technological surveillance, the question to be resolved was: ¿Will the addition and replacement of new materials equal or exceed the physicochemical properties of the final product? For the addition of industrial waste, an experimental design 22 is implemented with raw material replacements of 2.5.8% of eggshell to replace cement and 2, 6, 10% of rice husk to replace sand. Subsequently, the compression resistance test was carried out to observe the mechanical properties and finally the new material was characterized by the X-ray Diffraction (XRD) technique to evaluate the chemical properties.
Revisión Cienciométrica sobre la Versatilidad de la Caña de Azúcar: Valoración Sostenible de los Subproductos
(Universidad Santo Tomás, 2025-01-31) Vaca Gonzalez, Michelle Alejandra Penelope; Cervantes Diaz, Martha
Sugarcane (Saccharum officinarum L) is a versatile raw material of great economic importance worldwide, known for its capacity to generate value-added products ranging from food and biofuels to industrial materials. This study presents a scientometric review focused on the multiple applications of by-products obtained from various sugarcane industries, using scientific databases and tools such as VantagePoint and VOSviewer. 187 publications indexed in Scopus from 2014 to 2024 were identified, highlighting a growing interest in areas such as bioethanol production, bioplastics, and construction materials. The results reveal an increase in scientific output, led by Brazil and India. Key by-products include bagasse, cachaza, and vinasse, used to produce a wide variety of value-added products under circular economy approaches to mitigate environmental impacts and promote the sustainability of agro-industries. This work provides a comprehensive perspective on the opportunities and challenges associated with sugarcane by-products, demonstrating the potential of sugarcane to contribute to sustainable economic models through the integration of innovative technologies.
Síntesis De Análogos De Curcumina Para La Detección Del pH
(Universidad Santo Tomás, 2025-01-17) Fuentes Pérez, Sara Julieth; Rozo Correa, Ciro Eduardo; Osorio Martínez, Carlos Alberto
It is essential to develop accurate and sustainable methods for pH measurement in various applications. Traditional methods such as potentiometers and pH strips have limitations due to the use of toxic materials and the generation of polluting waste. In this context, the synthesis of optical sensors based on curcumin analogues is a promising alternative due to their favorable properties such as high sensitivity, selectivity, biocompatibility study and low cost. The objective of this project is to synthesize and characterize new curcumin analogues for use as pH indicators by UV-Vis spectroscopy. The curcumin analogues in their obtaining and optimization of reactions; will be carried out, through various chemical synthesis procedures and using reported literature and their colorimetric and fluorescence responses will be evaluated in a pH range from 0 to 14. In addition, the toxicity of these compounds will be tested by ecotoxicity tests to determine their possible impact on the environment. The methodology includes sensor synthesis, calibration tests and fluorescence analysis, as well as structural characterization using instrumental techniques such as infrared spectroscopy and UV-Vis spectroscopy. The results are expected to enable the development of versatile and efficient optical sensors for pH measurement, with potential applications in the environmental monitoring, healthcare and agricultural industries. In addition, this project will advance research in organic synthesis and molecular sensing, providing a sustainable and efficient alternative to traditional pH determination methods.
Fitotoxicidad de aceites esenciales de anís (Pimpinella anisum), anís estrellado (Illicium verum) y clavo de olor (Syzygium aromaticum): efectos sobre las semillas de lechuga y la de arvense Brachiaria brizantha
(Universidad Santo Tomás, 2024-09-04) Bastidas Duarte, Sergio Esteban; Bastidas Duarte, Sergio Esteban; Cervantes Díaz, Martha; Herrera Sandoval, Laura Viviana; Rueda Wandurraga, Verónica Lucía
Modern agriculture faces challenges due to weed competition with crops, which has traditionally been managed with synthetic herbicides that present environmental and health issues. In this study, the phytotoxicity of essential oils of anise (Pimpinella anisum), star anise (Illicium verum), and clove (Syzygium aromaticum) was proposed as natural and sustainable alternatives for weed control, using lettuce and Brachiaria brizantha seeds as bioindicators. The oils under study were obtained by microwave-assisted hydrodistillation with extraction yields of 1,9% for anise, 5,8% for star anise, and 10,1% for clove oil. Physicochemical parameters such as density, acidity index, refractive index, and peroxide index were determined. The chemical composition was established by gas chromatography-mass spectrometry, identifying the major components as trans-anethol (anise, star anise), and eugenol (clove). Phytotoxicity tests were performed for each of the oils using lettuce (Lactuca sativa) seeds as bioindicators to establish the median effective concentration (EC50). For anise, it was 4,39 ppm (radicle) and 5,90 ppm (hypocotyl); for star anise, 1,71 ppm (radicle) and 1,13 (hypocotyl); and for clove oil, the EC50 was 1.49 ppm (radicle) and 1.02 ppm (hypocotyl), showing better inhibition compared to anise and star anise. Similarly, the inhibition of germination on the weed Brachiaria brizantha was evaluated, where anise essential oil showed better inhibition with an EC50 of 2.34 ppm (radicle) and 1.44 ppm (hypocotyl).
Diseño de Sensores Moleculares Basados en Análogos de Curcuminas para la Detección del Herbicida Glifosato
(Universidad Santo Tomás, 2024) Carrillo Martínez, Stephanya; Osorio Martínez, Carlos Alberto
Currently, pollution by organic chemicals continues to be a global challenge for sustainable development since developing and developed countries use millions of synthetic organic compounds for industrial, commercial and defense purposes. In their common applications, pesticides are present, this large group is subdivided depending on their use; herbicides are applied directly to plants and soils and as a result, organic compounds are released that enter the environment and cause pollution in water, soil and air. Some of these pollutants represent health hazards such as asthma, birth disorders and even death, therefore it is essential to do environmental monitoring to prevent possible toxins from being released into the environment. Environmental protection agencies and environmental ministries around the world stipulate strict regulations on the concentrations of various environmental pollutants including herbicides for water, soil and air, however, monitoring methods for most of these compounds are expensive, time-consuming and some have limitations in sampling techniques and subsequently their analysis, so due to this there is a great demand to develop faster, simpler and more reliable methods for the detection of agricultural herbicides. Curcumin has a wide range of physiological actions such as antitumor, anti-inflammatory, antithrombotic, antidiabetic and antimicrobial effects; this compound both in its natural and synthetically modified form can be used as a starting material for the detection of chemical products due to its optical properties as a fluorescent polyphenol. The present research work includes the preparation of modified curcumin analogous chemical sensors and the obtaining of a series of copper metal complexes (Cu+2). These structural variations include modification of electron donor groups in source materials, the use of appropriate solvents to achieve improvements in absorption-emission processes if they have fluorescent properties and/or colorimetric changes in the evaluation for the analytical detection of the herbicide glyphosate.
Valoración del índice de calidad del agua (ICA) en afluentes pertenecientes a la provincia de Soto con influencia de actividad Industrial
(Universidad Santo Tomás, 2024-04-30) Pacheco Pedraza, Milthon Yecid; Rozo Correa, Ciro Eduardo
Worldwide, 80% of industrial wastewater is discharged into the environment without any prior treatment. Colombia has a main regulation for water quality control, decree 1575 and resolution 2115 of 2007, which establishes. The system for the protection and control of the quality of water for human consumption. In this work, the Water Quality Index (AQI) was evaluated in tributaries belonging to the municipality of California in the department of Santander against the possibilities of contamination by industrial wastewater discharges, based on the methodology for calculating the AQI according to the IDE. A.M. , where it was found that approximately 92% of the points analyzed in the tributaries of Santander present a regular water quality, and 8% present an acceptable water quality, the quality of the water of the tributaries in the California sector in the period 2022-2023 presents alterations, mainly anthropogenic due to the industrial influence (mining and agricultural) in its surroundings, which does not make it suitable for human consumption and it is necessary to carry out a purification treatment in such a way that it is suitable for consumption.
Determinación de SO2, NOx-NO2 en emisiones industriales como posibles contaminantes atmosféricos
(Universidad Santo Tomás, 2024-05-02) Avila Palmezano, Dayan Paola; Rozo Correa, Ciro Eduardo
Air quality has been affected by atmospheric pollutants such as SO2 and NOx that contribute to the formation of secondary compounds that are a risk to human health and the environment, this problem has increased today due to anthropogenic activities, Among them, those that exert the most negative impacts on the atmosphere are industrial emissions, therefore, the monitoring and control of air quality has become an important factor for environmental authorities. Therefore, in the present work, the concentrations of these main contaminants were analyzed with samples transported from the township of La Fortuna and the Sabana de Torres municipality following the guidelines of the US-EPA CFR methods indicated in resolution 1742 of 2018 with in order to carry out analytical tests and evaluate the impact of these compounds on the atmosphere, obtaining that these pollutants do not exceed the permissible limit at the end of the sampling but alarming concentrations occur in NOx during a short period of time.
Síntesis De Sensores Para Detección De Iones Metálicos En Solución Basados En Análogos De Curcumina-Aminoácidos
(Universidad Santo Tomás, 2024-05-08) Pinzón Troncoso, Jennifer Alejandra; Osorio Martínez, Carlos Alberto
Water pollution is a serious issue for human health and the environment, making it crucial to monitor water quality. Traditional methods such as atomic absorption spectroscopy and plasma spectrometry are effective but costly and slow. In response, fluorogenic and chromogenic methods have been developed, offering a rapid and efficient alternative for detecting traces of metal ions in solution. These sensors, particularly those with fluorescence properties, are valued for their specificity and sensitivity, making them ideal for use in remote areas. This study advances the development of fluorescent optical sensors and describes the synthesis of new heptanoid β-diketone compounds, like curcumin but more effective in detecting metal ions. These compounds exhibit fluorescent properties when reacting with transition metals, offering new possibilities for pollutant detection. The characterization of these sensors is carried out using advanced techniques such as infrared spectroscopy and nuclear magnetic resonance, and their efficacy and toxicity are assessed through ultraviolet-visible spectrophotometry and ecotoxicological tests on onion bulbs.
Evaluación de la toxicidad con Allium cepa y Brassica oleracea a un proceso de fitorremediación en suelos contaminados con glifosato
(Universidad Santo Tomás, 2024-03-18) Mejía Flórez, Kinverlyn Dayana; Restrepo Manrique, Ricardo; Cervantes Díaz, Martha
The most widely used herbicide in Colombia is N-phosphonomethyl glycine known as glyphosate, and although there are numerous generic formulations, the most prominent commercial brand is Roundup®. It is of utmost importance to investigate the toxicity of this herbicide through bioassays that are easily accessible and that present rapid germination and growth. For this purpose, two main bioindicators have been used: Allium cepa L y Brassica oleracea. The Allium cepa L., model is commonly used in cytogenotoxic tests, while the Brassica oleracea assay has gained relevance in cytotoxic analyses, especially in phytotoxic investigations. This study aimed to compare the responses of A. cepa and B. oleracea using macroscopic analyses, such as embryo growth and root index, as well as microscopic analyses specific to Allium cepa, such as mitotic index, the abnormality index, chromosomal aberrations and micronucleus formation. This was carried out after exposing the roots of these bioindicators to contaminants such as commercial glyphosate, its analytical counterpart and its metabolite. Test were conducted with four decreasing doses/treatments, ranging from 0,446 to 446 mg/L of the formulated product: Roundup® Active, containing 446 g/L of glyphosate acid equivalent, together with the corresponding negative controls (commercial drinking water) were tested. The results showed that the EC50, that is, the doses that reduced root growth by 50% for B. oleracea and A. cepa, were 1,203 mg/L (root) and 16,26 mg/L (embryo) for B. oleracea and 1,11 mg/L, for A. cepa. The bioindicators used demonstrated to be sensitive to various doses of glyphosate and, consequently, their suitability as biological indicators of specific toxicity is established.
Una revisión bibliográfica del cannabis medicinal y su potencial uso para el manejo del dolor
(Universidad Santo Tomás, 2024-01-24) Vesga Pinto, Keny Mauricio; Rozo Correa, Ciro Eduardo
This literature review was conducted under the guidance of the PICO methodology and the PRISMA method, which were used to organize the exploration, classification, and analysis of the evidence. Searches were conducted in different databases Scopus, Lens, PubMed, and Web of Science. An evaluation of the review findings provides insight that, although in a small number of citations, the results showed a benefit in reducing pain, the approach to analysis and reporting in other reviews was not optimal, making it difficult to know how consistent the findings are when considering pain in general. Adverse effects are reported in most articles comparing cannabis with placebo and in almost all reviews. Minor adverse effects (drowsiness, dizziness) were common and reported in all reviews, while serious harms were not as common, not found to be related to pain management. the results of the included reviews were very varied, and most reported an inability to generate conclusions due to the variety and inconsistency and lack of rigorous evidence. Not very positive effects are often reported, and it is possible that the cannabis-based medication as such outweighs the benefits.
Análisis de la movilidad de cadmio y plomo en suelos, hojas, frutos y lixiviados en plantaciones de cacao
(Universidad Santo Tomás, 2023-12-20) Calderón Suárez, Gustavo Alberto; Rozo Correa, Ciro Eduardo
Currently, cocoa from sectors such as Latin America and the Caribbean are among the most exported in the world. In normal amounts, the presence of metals is common in the vegetable soil, in the case of cadmium and lead, they are mobile elements that are found in the soil and are transported from the roots of the plants to the stems, leaves and the fruits. However, in high amounts, contamination for the soil and the human population can be extremely harmful. For this reason, the present study aims to analyze the mobility of cadmium and lead in soils, leaves, fruits,and leachates in cocoa plantations in Latin America between 2018-2023. This was done by identifying, characterizing, and retrieving information in databases such as Scopus, SpringerLink, Elsevier, Google Scholar, Science direct, and Web of Science in conjunction with thesauri, filters, keywords, and Boolean language. In this way it was possible to obtain a total of 12 articles from which the methodologies, instruments and relevant results were extracted, allowing to conclude the concern for the presence of cadmium and lead in cocoa plantations, the establishment of limits in the Colombian territory and the need for increased investment in research and monitoring to reduce contamination by these metals in cocoa.
Síntesis de catalizadores metal-carbenos N-heterocíclicos (NHC) y evaluación de su actividad catalítica en condiciones ambientalmente sostenibles
(Universidad Santo Tomás, 2023-12-18) Prada Rojas, Lizeth Daniela; Osorio Martínez, Carlos Alberto; Alvarado Rueda, Lizeth Johanna
The optimization of chemical reactions using catalysts allows to reduce reaction times and increase reaction yields. Homogeneous mesoionic NHC metal-carbene catalysts usually show high selectivity, improved activity and better stability compared to more classical analogous systems using organophosphine ligands. The main negative impact in the synthesis of catalysts is the use of organic solvents, so the use of deep eutectic solvents (DESs) has been proposed, which usually consist of two or three compounds; a quaternary ammonium salt complexed with a hydrogen donor compound or a metal salt. In this work, the synthesis of a mesoionic NHC metal-carbene catalyst by a series of "click chemistry" reactions, methylation, and complexation reactions with a transition metal by traditional and DES routes were proposed. The obtained compounds were characterized by infrared, magnetic resonance and melting points. And the catalytic activity of the metal-carbene-NHC obtained in Biginelli reactions was evaluated. These processes were compared in terms of reaction yields. The complexation of the catalyst was favored using DES, although in click chemistry and methylation the yield was lower than by the traditional route. To evaluate its catalytic activity, it is necessary to continue testing with different reactions.
Novedosos sensores fluorescentes basados en el 2,4,6-tricloro-1,3,5-triazina para la detección de iones metálicos en solución
(Universidad Santo Tomás, 2023-09-06) Arguello Reyes, Jeison David; Osorio Martínez, Carlos Alberto
The unique property of 2,4,6-trichloro-1,3,5-triazine (cyanuric chloride) is its ability to undergo a nucleophilic aromatic substitution (SNAr) reaction under controlled temperature conditions. Using a convenient synthetic protocol, monosubstituted s-triazines were treated with an excess of nucleophiles to obtain optical sensors for di- and trisubstituted triazines in 1+1+1 mode (one nucleophile for the first substitution, followed by another nucleophile for the second, and another more for the last position). The nucleophiles used for this study were 5-amino-2,3-dihydrophthalazine-1,4-dione (luminol), n-butylamine, and 4-amino-1,5-dimethyl-2-phenylpyrazol-3-one. (4-Aminoantipyrine). The best order of incorporation for obtaining the optical sensors derived from cyanuric chloride and studying its coordinating capacity of metal ions in aqueous solution of this work was 4-aminoantipyrine for the first position followed by n-butylamine for the second position and the third position of the triazine nucleus with luminol. The sensor resulting from the synthesis of cyanuric chloride first with luminol as the first substituent and 4-aminoantipyrine as the second substituent has sensitivity when tested with solutions of heavy metals (Hg, Cd, Pb, Cr and Fe) of which all lower the fluorescence provided by luminol to the chemosensor. The detection limit for each heavy metal was given in concentration ranges in ppm (parts per million) and was 40-30 ppm for Hg+2, 70-60 ppm for Pb+2 and Cd+2, and 20-10 ppm for Cr+2.
Análisis de la calidad de suelos en sistemas productivos agrícolas del municipio de Barranca de Upía-Meta
(Universidad Santo Tomás, 2023-08-02) Pulido Tenza, Camilo Andrés; Ospina Henao, Paolo Andrés; Martínez Molina, Saul; Candela Soto, Angélica María
The changes in the physical, chemical and biological properties of the soil in agroecosystems of the municipality of Barranca de Upía-Meta is associated with inadequate agricultural practices, lack of technical assistance and ignorance of the state of soil quality. Therefore, the project consisted of evaluating the quality of the soil in terms of macro and micronutrients, as well as the factors that intervene in their availability. The soils presented characteristics from strongly acid to neutral, with a sandy clay loam texture, moderately low organic carbon <9%, and moderate retention and storage of cations such as sodium, potassium, calcium, and magnesium. Finally, a series of agro-sustainable strategies were formulated in order to promote more sustainable production systems in the study area.
Evaluación de contaminantes orgánicos por cromatografía de gases en cuerpos de agua correspondiente al nororiente colombiano durante los años 2021 y 2022
(Universidad Santo Tomás, 2023-03-14) Gámez Hernández, Danna Melissa; Bayona, Olga Lucia; Candela Soto, Angélica María; Pabón Mora, Javier Mauricio
Some pollutants of environmental concern that affect water and are found at sub-ppb concentrations are persistent organic pollutants and semi-volatile compounds. This work studied the presence of polycyclic aromatic hydrocarbons, semivolatile phenolic compounds, polychlorinated biphenyls, and organophosphorus and organochlorine pesticides, in different origin water, using gas chromatography coupled to a mass spectrometer or an electron microcapture detector. Of 956 samples studied among the exposed parameters, only values above the quantification limit of the method were recorded for naphthalene, phenol, and the sum of 3-methylphenol and 4-methylphenol in non-domestic wastewater. The lack of regulations regarding the quality of discharges with these parameters is clear.

Examinar

Envíos recientes