Química
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Item Análisis electroquímico de vitamina B1 con un electrodo de carbono vitreo modificado con Ni (II)(Universidad Santiago de Cali, 2025) Barona Burbano, Bryan; Castro Narváez, Sandra Patricia (Directora)Vitamin B1 (thiamine) is an essential nutrient that can be acquired through food intake; however, its deficiency can lead to diseases, which makes it necessary to have reliable and sensitive analytical methods. This research work enabled the development of an electrochemical sensor based on a glassy carbon electrode (GC) modified with nickel ions (Ni²⁺) and polyvinylpyrrolidone (PVP), which was used solely as a binding agent to attach the Ni²⁺ compound to the GC, without analyzing its electrochemical effect in this study. Measurements were carried out in phosphate buffer at different pH values. The electrode modification resulted in an increase in peak current. Studies related to the variation of the scan rate showed a decrease in oxidation potential, an increase in the heterogeneous rate constant of the oxidative process, and an increase in the diffusion coefficient (1.93×10−6 cm2⋅s −1) which indicate catalytic synergy from Ni(II). Consecutive repeatability and reproducibility analyses yielded variation coefficients below 1.78% and recovery percentages above 98% in the presence of potential interfering species such as potassium, chloride, sodium, acetate, phosphate ions, and molecules such as glucose, fructose, and sucrose. A detection limit of 0.1 µM and a quantification limit of 0.34 µM were obtained. The analysis of commercial samples of injectable medications, tablets, and syrup showed recovery percentages above 96.8%. Altogether, the results confirm that the GC/Ni²⁺-PVP electrode is an efficient, stable, and low-cost alternative for the electrochemical determination of thiamine, with applicability in the quality control of pharmaceutical products.Item Análisis estructural y supramolecular del compuesto (E)-3',6'-dihidroxi-2-((pyridina-2-yl metileno) amino) spiro[isoidolina-1,9'-xanteno]-3-ona(Universidad Santiago de Cali, 2019) Cardona Restrepo, Camila; D'vries Arturo, Richard Fernando (Director); Rojas Álvarez, Oscar Eduardo (Director)The crystalline structure of the compound (E) -3 ',6'-dihydroxy-2-((pyridine-2-and methylene) amino) spiro [iso-idoline-1,9'-xanthene] -3-one was solved and refined, using single crystal X-ray diffraction data. It was found that the compound crystallized in the triclinic P-1 space group. its unit cell present two molecules per asymmetric unit, which correspond to molecular conformers. Moreover, an analysis to determine the intermolecular interactions from the crystalline system was performed. It was observed that the crystal packing is formed mainly by hydrogen interactions type O-H••• N, and C-H•••O. Finally, the supramolecular interactions of the dimer were quantified using fingerprint plots, obtaining values of 41.4%, 12.9%, 11.1% and 10.4% for interactions type H•••H, C•••H, O•••H, H•••C respectively. The aforementioned diagrams were compared with the obtained for structurally similar molecules; their forms confirmed the differences at the supramolecular level of the compounds analyzed. With this project, it was possible to determine the structural and supramolecular characteristics of the compound. In addition, were acquired the basic concepts related to crystallography and supramolecular chemistry, both at a theoretical and experimental level.Item Análisis sensorial aplicado a productos alimenticios a base de avena y sus derivados: Una revisión Sistemática(Universidad Santiago de Cali, 2021) Arias Cerón, Arlex; Méndez Gómez, Gloria Sthefani; Ramírez Navas, Juan Sebastián (Director)In this systematic review intervention type, an exhaustive investigation of published studies, books and documents about Sensory Analysis applied to healthy oat-based foods is carried out, selection criteria were applied to identify relevant evidence, filter, classify and compare sensory techniques, determine the most widely applied technique in this type of food, according to the ideal studies compiled, it is found that 61% apply the affective sensory analysis technique, above the discriminative and descriptive techniques; which indicates that for healthy oat-based foods, the main requirement in the studies was to identify the acceptance of the product, this technique being the most frequent.Item Análisis voltamétrico de losartán potásico en electrodo de carbono vítreo dopado con 3,4- polietilendioxitiofeno (pedot)(Universidad Santiago de Cali, 2022) Giraldo Balcázar, José Daniel; Gutierrez Moreno, Nini Johanna (Directora)Electrochemical results are presented for the sensitive, repeatable and high percentage recovery determination of Losartan potassium (LOS) by voltammetric techniques on bare glassy carbon electrode doped with 3,4- polyethylenedioxythiophene (PEDOT). Effects associated with the type of electrolyte establish that LOS exhibits a 29% increase of the peak current in Buffer Britton Robinson (BBR) pH 8.5 with respect to Buffer phosphate (BF) at pH 6.0; establishing that the molar electrosorption capacity of P affects the electrochemical signal. Studies associated with the sweep speed do not present substantial differences in the diffusion coefficient in both electrolytes. Low-range calibration curves for the bare electrode are between 10-100M (R2 = 0.9958), and with PEDOT between 0.1- 1.0M (R2 = 0.9911). Both electrodes show coefficient of variation percentages of less than 4% in repeatability and reproducibility tests. The deposition of PEDOT on the glassy carbon electrode improves the detection limit from 10.0M to 0.1M. The analytical ranges are applicable to commercial pharmacological samples with recovery percentages higher than 97.0% similar to high performance chromatographic (HPLC) techniques.Item Aplicación de la ecuación de Schrödinger en el estudio del movimiento de moléculas diatómicas(Universidad Santiago de Cali, 2019) Bueno Barbosa, Douglas Andrés; Parada Valencia, Alexander (Director)Understanding the physiochemical phenomenon at the subatomic level is very important in order to know the behaviour of the matter these energy scales. It is necessary to use the Schrödinger equation in the order to describe chemical and physically the molecules. Throughout of the development of this work, we addressed the study of the Schrödinger equation and applications in the movement of diatomic molecules. The interaction potential is described by this equation, as well as the translational, rotational and vibrational energies of each molecule. Likewise, the Hamiltonian is studied in a general way, and particularly for the hydrogen molecule. We learned the main knowledge relating with Quantum Chemical and after that we focus in the study of some diatomic molecules no studied in the literature until now. Then, a phenomenological study was carried out for the BrCl molecule.Item Aplicación de la espectroscopia de infrarrojo cercano (NIRS) en productos cárnicos(Universidad Santiago de Cali, 2024) Rosero Martínez, José Miguel; Castro Narváez, Sandra Patricia (Director)An approximation is made to near infrared spectroscopy (NIRS) as a tool for evaluating the quality and authenticity of meat products. Given the growing demand for organic meat products and the need to guarantee their integrity, NIRS stands out as an effective alternative to traditional methods. The methodology employed included literature review, data analysis and method comparison, highlighting the importance of developing more robust calibration and standardization techniques. Quality parameters that NIRS can assess, such as moisture, fat, protein, color and pH, were identified, demonstrating its ability to provide rapid and non-destructive results. Comparison between NIRS and traditional techniques such as proximate analysis revealed that NIRS offers significant advantages in terms of speed and reduced need for sample preparation. However, limitations have been identified, including the need for specific calibrations for each type of meat and the dependence on the quality of the equipment used. Recommendations include advancing the development of calibration techniques and exploring the integration of NIRS technology in real-time computing environments.Item Aplicación de la espectroscopia en el infrarrojo cercano (NIRS), en el análisis de aceites esenciales para aplicación industrial (cosmética y farmacéutica): Revisión sistemática(Universidad Santiago de Cali, 2024) Vasquez Obando, Sergio; Orduña Ortega, Julieth (Directora); Vargas, Yaneth (Directora)This review presents the application of Near Infrared Spectroscopy (NIR) in the analysis of essential oils, specifically in the cosmetic, pharmaceutical and phytotherapeutic industries. This is a vibrational technique that uses light in the range of 780 to 2500 nm, allowing the qualitative and quantitative evaluation of biological samples. Among the most notable advantages are the minimal sample preparation and the ability to perform rapid and noninvasive analysis, however, the low sensitivity and complexity in the interpretation of spectra is a major disadvantage. The article highlights the use of NIR in quality control and in determining the chemical composition of essential oils, which are obtained by various extraction methods. The NIR technique is effective in identifying the purity and taxonomy of essential oils and in quantifying specific compounds such as terpenes. The present review also mentions the growing interest in essential oils due to their antioxidant and antimicrobial properties, and their use in natural and safe products compared to synthetic antioxidants. In the pharmaceutical industry, NIR could be used in the analysis of compounds in the pharmaceutical industry, while in the cosmetic industry, it could verify lipid oxidation and emulsion quality. NIR spectroscopy is a great tool in the analysis of essential oils, as it offers an efficient and accurate method to ensure the quality and safety of products in the cosmetic and pharmaceutical industries.Item Aplicación de la espectroscopia infrarroja cercana (NIRS) en la calidad de la caña de azúcar durante la cosecha y postcosecha: Una revisión(Universidad Santiago de Cali, 2024) Bravo España, Gefersoon; Orduña Ortega, Julieth (Directora)Near infrared spectroscopy (NIRS) has established itself as a crucial technique in the sugarcane industry, in the evaluation of quality parameters at different stages of the raw material to product conversion process. This article aims to review and compare the different recent research on the application of NIRS in determining crucial parameters in sugarcane quality at different stages of the process from identification in the cane stem to cane juice, such as fiber, Pol, total soluble solids, brix, the different linear regression techniques, the equipment used throughout this review. The most widely used NIRS analysis methodology is reflectance and transmittance since it provides sufficiently robust predictive models for the prediction of the factors already mentioned. The NIRS technique offers rapid and non-destructive evaluations, with great potential for the optimization of quality parameters in cane growth.Item Aplicación de la técnica Espectroscopía Raman para la determinación de microplásticos en el agua potable(Universidad Santiago de Cali, 2025) Collazos Reina, Jhon Jairo; Morales Morales, Jimmy Alexander (Director)The presence of microplastics in the environment represents a chemical, environmental, and social issue that has been increasing over the past few decades. This monograph addresses this situation, focusing particularly on the detection of microplastics in tap and drinking water across various cities and countries, thus evidencing their presence in urban water systems worldwide. Special attention is given to the Raman spectroscopy technique and its variants (μRaman). This analytical method is selective and non-destructive, allowing for the efficient identification and quantification of various types of microplastics at microscopic and even nanometric scales. Due to its high sensitivity and specificity, this technique has become a key tool in the analysis of emerging pollutants, surpassing some limitations of other methodologies such as Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX). Several recent studies have reported varying concentrations of microplastics in drinking water samples using Raman spectroscopy as the method of identification. These results not only validate the effectiveness of the technique but also highlight the need to implement monitoring and control systems to prevent microplastics from entering water distribution networks. Although the presence of microplastics in drinking water has been widely documented, their specific effects on human health remain inconclusive. However, their persistence, bioaccumulation potential, and toxicity make their study a continued priority for the scientific community from a preventive perspective.Item Aplicación del diseño de mezclas en la formulación de sidra de manzana (Malus domestica)(Universidad Santiago de Cali, 2020) Ramírez Naranjo, Nathalia; Sinisterra Amú, Diana; Ramírez Navas, Juan Sebastián (Director)Cider is a drink with very marked characteristics with respect to other spirits; It has abundant carbon dioxide, but produces less foam than a regular beer, acquires shades of yellow in transparent and bright appearance. (Drilleau, 2005). Cider. 2. The objective of this research was to evaluate the ratio of cider mixtures from three varieties of apple (Malus Domestica): Gala, Golden and Green. This mixing design consisted of applying a planning and analysis methodology which could ensure that we obtain the knowledge and solutions. The adoption of this methodology aims to assess the influence of each component of the formulation on the selected response varieties. For this purpose, different physicochemical tests were performed on each mixture obtained: (pH, Density, Volatile Acidity, alcoholic Strength and Sugar Percentage) and from which the expected results were obtained with an average of pH between 3.6 - 3.8; Density between 0.99-1.02 g/mL; Volatile Acidity between 0.04 -0.09 g/L; Alcohol content between 0.73 - 2.4 %V; Microbiological: (Count of aerobic bacteria and mesophylls, mold count, yeast count and total coliforms) whose result of each test was <10 UCF/mL and Sensory Analysis in which preference was found for the sample called B, corresponding to the mixture 0,1/2,1/2 being this the mixture between green apple and gallium apple. The results obtained in each test were expected indicating that the drink does meet the requirements established by the Colombian technical standard NTC 222 and NTC 708, concerning alcoholic beverages and their general definitions, alcoholic beverages (Fruit wines) respectively.Item Aplicaciones de NIRS en muestras de forraje para el análisis de los principales parámetros de calidad nutricional: Revisión sistemática(Universidad Santiago de Cali, 2024) Jaramillo Zapata, Sergio Alejandro; Orduña Ortega, Julieth (Directora)Near-infrared spectroscopy (NIRS) has become established over the past decades as a rapid and non-destructive analytical technique for evaluating the chemical composition of forages. This method is based on the absorption of light in the near-infrared region of the electromagnetic spectrum and allows for the determination of various critical nutritional parameters in forage used for ruminant feed. Assessing these parameters is crucial for improving the quality of forage intended for animal feed, which directly impacts the productivity and health of ruminants. Tropical grasses, frequently used as forage, exhibit considerable variability in their nutritional quality due to environmental factors. In this context, the application of NIRS offers an invaluable tool for the rapid and accurate determination of key components, such as crude protein, fiber, and minerals, among others. This review focuses on the bibliographic search of recent studies on the applications of NIRS in forage samples, with a special emphasis on tropical grasses. The main nutritional quality parameters of forage are discussed, the NIRS technique is described, sample preparation is addressed, and the methodologies applied to obtain results in various studies are reviewed.Item Aprovechamiento de alcohol fusel en la obtención de productos de valor agregado utilizando perovskitas como catalizadores(Universidad Santiago de Cali, 2024) Valencia Castro, Jessica Andrea; Orduña Ortega, Julieth (Directora); Mora Vargas, Jorge Andrés (Director)At present, the quest for renewable carbon sources to generate energy and high-value products has seen a significant rise, particularly those enabling the extraction of chemical components traditionally derived from fossil fuels. Industrial processing of sugarcane yields various renewable materials, including fusel alcohol, offering the potential for conversion into valuable compounds. The catalytic conversion of fusel alcohol (mixture of different alcohols with C3 to C5) using the Guerbet reaction has not yet been widely explored, however, some of its components have already been used as starting material for this reaction using different catalysts. Thus, this work was aimed at the conversion of fusel alcohol by the Guerbet reaction using perovskite-type oxides of La (III) as cation A and Zn (II) or Ni (II) as cation B. The oxides were obtained by the calcination of their precursors synthesized by the coprecipitation method and were well characterized by infrared spectroscopy (IR), X-ray diffraction (DRX), and thermogravimetric analysis (TGA). The TGA curves showed the complete decomposition of the precursors at 900 °C in 4 hours. XRD patterns confirm the formation of the perovskite phase. In addition, IR spectra of the synthesized materials show vibrations indicating the presence of Ni-O and Zn-O bonds. In the catalytic conversion of fusel alcohol, different groups of compounds were obtained, such as alcohols, esters, ethers, and ketones.Item Aprovechamiento de los lodos de salmuera de una planta cloro-soda para la producción de carbonato de sodio(Universidad Santiago de Cali, 2018) Luna Gómez, José Luis; Ayala Cruz, Martha Isabel; Franco, Jaime Martín (Director)A methodology was carried out to obtain sodium carbonate from the brine sludge, previously characterized by ICP-OES plasma spectroscopy. The treatment consisted of adding hydrochloric acid to the sludge to generate carbon dioxide which was absorbed in sodium hydroxide solution at different concentrations to produce sodium carbonate, with a maximum yield of 62,2%.Item Aprovechamiento del alcohol fusel utilizando la reacción de Guerbet catalizada por óxidos metálicos mixtos modificados con Zn2+/Co2+ y Zn2+/Fe2+(Universidad Santiago de Cali, 2024) López Gómez, Angie Lorena; Orduña Ortega, Julieth (Directora); Mora Vargas, Jorge Andrés (Director)The search for methods for synthesizing value-added chemicals using renewable raw materials is constantly increasing, so the use of products and by-products derived from the industrial processing of sugar cane is of particular interest, such as fusel oil, which has been little studied as a substrate in the Guerbet reaction, which allows the synthesis of alcohols from longer chains and other products through parallel reactions. In this work, the catalytic conversion of fusel alcohol with mixed metal oxides (MMOs) derived from hydrotalcites (HDLs) modified with Zn2+/Fe2+ and Zn2+/Co2+.Zn2+/Fe2+ and Zn2+/Co2+ . The HDLs were synthesized by the coprecipitation method and through a subsequent heat treatment their respective OMMs were obtained. The materials obtained were characterized by infrared (IR) and Raman spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (DRX) and scanning electron microscopy (SEM), where their correct synthesis was confirmed. The catalytic conversion of the fusel alcohol was performed in a Bach-type reactor. Different physicochemical parameters were studied in the reaction and their products were identified by gas chromatography coupled to mass spectrometry detector. It was mainly evidenced the formation of families of alcohols and esters, followed by aldehydes, ketones and olefins, which was probably influenced mainly by the degree of acidity of MMOs according to the literature.Item Avances en el uso de espectroscopia NIR en el análisis como tecnología analítica para controles en proceso en tiempo real de la fabricación de formas farmacéuticas sólidas: Review(Universidad Santiago de Cali, 2025) Diaz Garces, Oscar Andres; Orduña Ortega, Julieth (Directora)Near-infrared (NIR) spectroscopy is currently the fastest growing and most versatile analytical method not only in pharmaceutical sciences but also in industry. Furthermore, new regulatory guidelines have driven the increased use of NIR technologies. The non-destructive and non-invasive nature of the measurements makes NIR a powerful tool in the characterization of pharmaceutical solids. These benefits, among others, often make NIR advantageous over traditional analytical methods. This review focuses on recent applications of NIR in pharmaceutical technology, covering the monitoring, by NIR, of many manufacturing processes, such as granulation, mixing or drying, in order to determine the end point of these processes and the determination of the quality and quantity of pharmaceutical compounds.Item Avances en las aplicaciones de espectroscopía de infrarrojo cercano (NIRS) en el análisis de los parámetros de calidad de la cerveza: Revisión sistemática(Universidad Santiago de Cali, 2024) Posada Cabrera, Javier Mauricio; Illicachi Romero, Luis Alberto (Director)In the review of beer quality management, the complexity and resources required to assess its components, such as alcohol, phenols, pH, sugars, amino acids, gases, colour, and turbidity, are addressed. Integrating physicochemical, microbiological, sensory, and spectroscopic methods is effective and efficient. Among the spectroscopic techniques, near-infrared spectroscopy (NIRS) stands out for its ability to measure multiple components quickly and non-destructively. Studies have demonstrated its effectiveness in precisely determining alcohol and other fermented compounds, reducing the reliance on slower and more expensive traditional methods. NIRS is used at different stages of the brewing process and allows for real-time monitoring that facilitates production adjustments. Experiments have validated its applicability in evaluating specific components in complex fermentations. Furthermore, the combination of NIRS with artificial intelligence and machine learning models has enhanced its precision, enabling early fault detection and optimization of the fermentation process.Item Avances en materiales electrocrómicos: Perspectiva industrial en Colombia(Universidad Santiago de Cali, 2021) Hurtado Palacios, Luis Felipe; Castro Narváez, Sandra Patricia (Directora)Item Bioprospección in silico de péptidos con actividad dual antibacteriana-cicatrizante(Universidad Santiago de Cali, 2022) Fernández Bedoya, Isabella; Oñate Garzón, José Fernando (Director)Peptides are naturally produced by multiple organisms and exhibit a wide range of physiological, immunomodulatory, and wound healing functions. Additionally, they can provide protection against microorganisms, and they can be considered as an alternative antibiotic. To accelerate and aid the healing process, and avoid possible bacterial infections, peptides with dual antibacterial healing activity were identified from the cutaneous transcriptome of the Boana Pugnax frog (B. Pugnax) by in silico analysis. The peptides Alyteserin-2Ma, Brevenin-1Pb, Ocellatin-F1, Temporin-1P, Uperin 3.6, were selected based on their physicochemical properties and served as a template for their subsequent alignment with the B.Pugnax transcriptome, as well as their function as ligand with receptors EGF (Epithelial Growth Factor), VEGF (Vascular Epithelial Growth Factor), TGFβ-1 (Transforming Growth Factor Beta 1) and TGFβ-3 (Transforming Growth Factor Beta 3). The interactions between peptides and receptors were conducted by molecular docking analysis (Molecular Docking). The results revealed that Boana peptides can interact with receptors; Likewise, it was observed that most of these interactions exceeded the standard values (Boana Pugnax). Given these computational findings, new potentially effective antibacterial-healing peptides were identified for the healing process, which could be subsequently evaluated in in vitro tests.Item Búsqueda de agentes antioxidantes en tres especies frutales silvestres de Colombia del género Passiflora L.(2022) Restrepo Ríos, John James; Pantoja Pulido, Kriss Dayana (Directora)Diseases of the central nervous system (CNS) such as schizophrenia, Parkinson's, Alzheimer's, such as the emotions of happiness, sadness, anguish, among others, are related to the excessive or insufficient production of neurotransmitters. Depression and anxiety are mental disorders that have increased in the world population, therefore, chemical and biological research has focused on the development of new drugs for the treatment of these diseases, restoring the balance of neurotransmitters among other processes synergists that occur in the CNS. At present, natural alternatives are being sought, such as certain secondary metabolites from plants. This project focuses on the search for anxiolytic agents and antioxidants in species of Passifloras L., wild fruit trees of Colombia, for this, 3 wild passiflowers from Valle del Cauca were selected, and various extracts with different polarity were obtained at a microscale performing exhaustive extractions In ultrasound, the antioxidant activity was subsequently evaluated with the DPPH tests, being P. cisnana in polar extract the one that obtained the best result with 4.08 ±0.083 mmol ET / g ES (MS); ABTS which gave the best result to P. sphaerocarpa in polar extract with 23.3 ±0.122 moles ET / g ES (MS); and FRAP in which P. cisnana in its medium polar extract presented the best result with 72.1 ±4.10 moles Fe+2 / g ES (MS). On the other hand, the total phenol content (CTC) was also determined, which determined P. sphaerocarpa in polar extract as the best result with 17.7 ±4.30 mg EAG / g ES (MS); total content of CTFL flavonoids, with the medium polar extract of P. cisnana being the one with the best result with 44.7 ±0.131 mg EHR / g ES (MS); and total catechin (CTC) content presenting the medium polar extract of P. maliformis as the highest with 37.7 ±2.72 mg EHC / g ES (MS).Item Calibración en harina de arroz blanco para la determinación de las variables de SB y BD del perfil de viscosidad por la técnica espectroscopía de reflectancia en el infrarrojo cercano (NIRS)(Universidad Santiago de Cali, 2023) Giraldo Ossa, Erika Fernanda; Orduña Ortega, Julieth (Directora); Loaiza de la Pava, Jhoana Katerine (Directora)Currently, the importance has increased for the genetic improvement program of the Latin American Irrigated Rice Fund (FLAR) to evaluate the quality of rice through quick, economical, environmentally friendly tools that require a minimum of preparation for your analysis. Given the above, the possibility of using the NIRS near-infrared spectroscopy technique (400-250nm) was studied through the development of a calibration equation to measure the Breakdown (BD) and Setback (SB) variables, which currently are evaluated in the Rapid Visco Analyzer RVA equipment (by its name in English), these viscosity variables of rice starch allow us to associate the cooking quality of the grain. The implementation of this technique seeks to facilitate the analysis of early generation rice lines, since currently, due to the capabilities of the RVA, it is only possible to evaluate advanced lines. The calibration was carried out on a set of 196 samples with a mathematical treatment “2,16,32,1”, an MPLS partial least squares regression model and SNV and Detrend smoothing, where the following statistical data of the variables were obtained. viscosity of BD and SB which were RSQ calibration (0.864 and 0.853), SEC (129.580 and 234.552), 1-VR (0.786 and 0.761), SECV (350.939 and 635.427) and RPD (2.168 and 2.049) respectively. Subsequently, the developed equation was verified through internal and external validation, obtaining the following internal RSQ statistics (0.822 and 0.808) and a SEP (151.909 and 309.770), RSQ external (0.791 and 0.531) and a SEP (210.444 and 944.374) respectively for the BD and SB variables. The calibration equation presents a good prediction for routine evaluation in early generation samples for the BD variable.