Química

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    Desarrollo de un modelo de calibración por espectroscopía de reflectancia en el infrarrojo cercano de fitatos totales en frijol
    (Universidad Santiago de Cali, 2025) Patiño Lenis, Gelver; Orduña Ortega, Julieth (Director)
    Iron deficiency affects the world population and is the main cause of anemia, hence the importance of having crops, such as beans, which enhance food systems and meet the nutritional needs of the population. Therefore, the International Center for Tropical Agriculture (CIAT) bean breeding program aims to increase the concentration of minerals such as iron through biofortification. However, there is an adverse effect, and that is due to crops containing chemical species that form coordination complexes, such as phytates, which are responsible for retaining minerals, thus reducing their bioavailability in the organism. Currently in the Nutritional Quality Laboratory (NQL), 7000 analyses are performed annually for the quantification of total phytates by UV-VIS spectrophotometry in bean flour matrices, presenting difficulty for the laboratory to perform not only this high number of analyses but also the other volumes of samples from other assays, Therefore, it is proposed to develop and evaluate an analytical tool that generates fast and reliable results in the analysis of total phytates in bean flour by means of a calibration curve that generates a prediction model using near infrared reflectance spectroscopy (NIRS). A total of 334 bean varieties were analyzed with proper sample preparation. Subsequently, the total phytate content was evaluated by the reference method by UV-VIS spectrophotometry and then the spectra were generated in NIRS. Calibration and validation of different prediction models was performed with RStudio, prospectr, pls and other packages. A calibration model was obtained with SNVD-SG 1,4,5,3 and PLS regression in the range of 400 nm to 2500 nm with a RSQ of 0.77, 1-VAR of 0.54, SEC of 1.54, SEP of 2.59 and RPD of 1.46 that has the potential to preliminarily classify between concentration levels the extensive volumes of samples in NQL at low cost and short time to the bean breeding program at CIAT.
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    Optimización del proceso de extracción de pectina de cáscaras de piña empleando técnicas emergentes: Revisión sistemática
    (Universidad Santiago de Cali, 2025) Garcia Idrobo, Daniel Eduardo; Suárez Osorio, Liseth (Director)
    Industrial food processing generates byproducts that are often discarded, resulting in significant economic and environmental impacts. Recycling is an efficient strategy to mitigate these problems, promote sustainable uses, and reincorporate bioactive compounds, such as pectin, present in plant materials like pineapple peels. This biopolymer has diverse applications in the food, pharmaceutical, and cosmetics industries. However, its demand has driven the adoption of emerging extraction techniques due to the limitations of conventional methods in terms of efficiency and impact on quality. These techniques offer advantages due to their low energy consumption, higher yield, improved quality, and minimal or no generation of hazardous effluents. This systematic review addresses the use of response surface methodology to recover pectin from pineapple peels, employing emerging techniques such as microwave and ultrasound-assisted extraction, highlighting their efficiency, quality, and functionality, as well as the advantages and disadvantages of each method. Thus, it will provide a solid foundation for future research and development initiatives by exposing strategies and optimization parameters reported in scientific literature.
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    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.
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    Detección de drogas sintéticas en aguas residuales mediante espectrometría de masas de alta resolución (HRMS): Una revisión sistemática
    (Universidad Santiago de Cali, 2025) Ospina Yepes, David Santiago; Ocampo Chaguendo, Denis Mauricio (Director)
    The objective of this systematic review was to analyze the application of high-resolution mass spectrometry (HRMS) in the detection of synthetic drugs and new psychoactive substances (NPS) in wastewater. Through an exhaustive search in international databases (Scopus, ScienceDirect, Web of Science, Springer and Taylor & Francis), 4,977 articles were initially identified, of which, after a rigorous selection process following PRISMA guidelines, 36 relevant studies were included. The results evidenced that cocaine, MDMA and amphetamines continue to be the most prevalent illicit substances detected in wastewater, although an emerging growth in the detection of synthetic cathinones such as 3-MMC and α-PVP was reported. It was observed that HRMS, through targeted, suspect and non-targeted screening strategies, allowed efficient identification of both known compounds and emerging substances. However, the lack of standardized quantitative data and the geographical concentration of studies in Europe and Oceania were highlighted as important limitations. These findings underscore the need to expand HRMS-based environmental monitoring to less studied regions and to establish more standardized analytical protocols to strengthen the epidemiological assessment of drug use globally
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    Implementación de una metodología potenciométrica como método alternativo al método general de la usp, para cuantificar aluminio y magnesio en un fármaco antiácido en suspensión
    (Universidad Santiago de Cali, 2025) Benavides Arango, Miguel Ángel; Ríos Acevedo, Jhon Jairo (Director)
    The increase in gastric diseases, associated with poor eating habits and unhealthy lifestyles, has generated a growing need for effective treatments. The use of antacids is common to alleviate these disorders, but the quality and composition of these medications are crucial for their efficacy and safety. This article focuses on the development and optimization of a potentiometric technique for the quantification of aluminum and magnesium, metals present in many commercial antacids. The complexometric quantification methodology cited by the USP was initially implemented, and both techniques were validated within a linear range of 50% to 150%. The titrant data obtained were proportional to the analytical concentration of both aluminum and magnesium. High-precision results were achieved with relative deviations of around 0.4%, which are
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    Síntesis y caracterización de nuevas hidrazonas derivadas de la vainillina con posible actividad biológica
    (Universidad Santiago de Cali, 2025) Barbetti Rondón, Valentina; Illicachi Romero, Luis Alberto (Director)
    In this study, a derivative of vanillin was synthesized through a condensation reaction with hydrazine hydrate, using absolute ethanol as the solvent and glacial acetic acid as the catalyst. The product obtained was a yellow solid with a yield of 85%, corresponding to an azine derivative of vanillin. This compound was characterized by infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H-NMR). The spectra confirmed the formation of the imine bond (C=N), characteristic of azomethine structures, as well as the presence of aromatic and methoxy functional groups, thereby validating the successful synthesis of compound V2H1 with high purity and structural symmetry. Additionally, mass spectrometry (MS) analysis revealed a molecular ion [M]⁺ at m/z = 300 and a predominant fragment at m/z = 177, resulting from homolytic fragmentation that supports the proposed structure and provides detailed information on atomic connectivity. The pharmacokinetic properties of the compound were also evaluated using computational ADME analysis and the predictive BOILED-Egg model. The results showed that compound V2H1 complies with Lipinski’s rule of five and exhibits a favorable profile for oral absorption, with good water solubility and a high probability of gastrointestinal absorption without crossing the blood–brain barrier 4 (BBB). These findings reinforce the potential of vanillin as a precursor for obtaining bioactive derivatives with possible pharmacological applications
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    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.
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    Síntesis de hidrazonas derivadas de la vainillina como posibles agentes antimicrobianos
    (Universidad Santiago de Cali, 2025) Quiroga Campo, Michael Daniel; Illicachi Romero, Luis Alberto (Director)
    The compounds (E)-4-((2-(4-chlorophenyl)hydrazineylidene)methyl)-2-methoxyphenol (DQ1), (E)-4- ((2-(4-bromophenyl)hydrazineylidene)methyl)-2-methoxyphenol (DQ-2), and (E)-2- methoxy-4-((2-(4- (trifluoromethyl)phenyl)hydrazineylidene)methyl)phenol (DQ-3) were synthesized via condensation reaction using ultrasound. The reaction was carried out over a period of 20 to 40 minutes at a controlled temperature of 30 °C, employing 4-hydroxy-3- methoxybenzaldehyde as the carbonyl component with a mixture of ethanol:water (2:1) in the presence of various aromatic hydrazine derivatives. This method enabled the formation of the corresponding hydrazones (DQ-1, 2,3), which were intended to undergo a subsequent alkylation reaction with 2-chloro-N,N-dimethylethylamine hydrochloride in N,Ndimethylformamide (DMF) as the reaction medium. The objective was to obtain functionalized derivatives, specifically (E)-2-(4-((2-(4-chlorophenyl)hydrazineylidene)methyl)-2- methoxyphenoxy)- N,N-dimethylethan-1-amine (DQ-4), (E)-2-(4-((2-(4- bromophenyl)hydrazineylidene)methyl)-2- methoxyphenoxy)-N,N-dimethylethan-1-amine (DQ-5), and (E)-2-(2-methoxy-4-((2-(4 (trifluoromethyl)phenyl)hydrazineylidene)methyl)phenoxy)-N,N-dimethylethan-1-amine (DQ6). However, analysis of the reaction products revealed that the expected alkylated compounds were not successfully obtained, that suggests the alkylation reaction may have followed an alternative pathway or did not proceed efficiently, possibly due to various chemical or experimental factors. In particular, the acidic environment generated by the hydrochloride form of the alkylating agent may have promoted the formation of undesirable by-products, owing to the susceptibility of the compounds to suffer side reactions under protonated conditions.
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    Determinación simultánea de acetaminofén y levofloxacina usando un electrodo modificado con carbón vegetal y nanopartículas ecológicas de óxido de hierro y lantano
    (Universidad Santiago de Cali, 2025) Montilla Martinez, Sebastian; Morales Morales, Jimmy Alexander (Director)
    In this study, an electrochemical sensor was designed and evaluated, modified with environmentally low-impact materials and aimed at the simultaneous detection of two highly relevant pharmaceutical contaminants: acetaminophen (AC) and levofloxacin (LE). For this purpose, a glassy carbon electrode (GCE) was doped with a combined suspension of lanthanum ferrite (LaFeO₃) nanoparticles and activated vegetal carbon, both synthesized through a green synthesis process using molasses as an organic fuel, promoting an eco-friendly and cost-effective production pathway. The modification was performed using the drop-casting technique, applying 8 µL of the activated suspension (1:1 ratio), previously dispersed via ultrasonication. The electroanalytical performance of the system was characterized using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The modified electrode exhibited a well-defined voltammetric response, with two distinct, non-overlapping anodic peaks, confirming the feasibility of simultaneous and selective detection of both analytes under optimal conditions at pH 5. A linear response was achieved in the 20–60 µM range (R² = 0.966), with limits of detection and quantification of 9.20 µM and 27.88 µM, respectively. The analysis of peak current (Ip) versus the square root of the scan rate (√v) revealed a diffusion-controlled mass transport mechanism. Furthermore, the system showed a significant reduction in charge transfer resistance (Rct ≈ 27.7 kΩ) and an improvement in interfacial capacitance, attributed to the electrocatalytic synergy between the metal oxide and the carbonaceous support. The sensor demonstrated good repeatability (RSD < 10%) and operational stability up to 12 hours, with a signal loss of less than 14%, establishing it as a technically robust, reproducible, and environmentally sustainable alternative. These findings highlight the feasibility of employing eco-friendly materials and accessible fabrication techniques for the development of electrochemical sensing platforms, with promising applications in environmental monitoring, pharmaceutical analysis, and contaminated effluent assessment.
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    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 solidas: Revisión sistemática
    (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.
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    Estudio de la degradación fotocatalítica de contaminantes emergentes farmacéuticos por nanopartículas ecológicas de perovskita
    (Universidad Santiago de Cali, 2025) Bonilla Caicedo, Leidy Johanna; Morales Morales, Jimmy Alexander (Director)
    This study investigates the ultrasound-assisted synthesis of lanthanum ferrite (LaFeO) nanoparticles using molasses as a carbon matrix, which improves the dispersion of the material and its photocatalytic performance. A visible light lamp with a wavelength between 190 and 1100 nm was used to activate the photocatalytic properties, resulting in a material yield percentage assisted by ultrasound of 52.38% and assisted by mechanical stirring of 56.49%. In aqueous solutions of acetaminophen at a concentration of 70 ppm, 25% was obtained, at 20 ppm 33%, and at 50 ppm 72% degradation. The characterization of the nanoparticles revealed an orthorhombic crystalline phase of LaFeO, thus promoting the effectiveness of the photocatalyst. The use of the carbon matrix not only optimizes the catalyst surface but also improves its stability under different pH and catalyst loading conditions. Ultrasound assistance during synthesis resulted in a more uniform structure and improved photodegradation of the emerging contaminant. This innovative approach, utilizing an industrial waste product for nanoparticle synthesis, not only seeks to offer an effective solution for treating contaminated water but also presents a sustainable alternative for waste management. This work represents a significant advance in the development of more effective technologies to address emerging environmental contamination.
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    Review: Avances en la aplicación de la espectroscopia de infrarrojo cercano (NIR) en la evaluación de propiedades de alimentos cárnicos.
    (Universidad Santiago de Cali, 2025) Castro Buitrón, Maricel Jhohanna; Rios Acevedo, Jhon Jairo (Director)
    Near-infrared spectroscopy is profoundly transforming quality control in the meat industry, as demonstrated by the 56 studies analyzed in our review. The results are truly remarkable: this technology not only measures product composition with extraordinary precision (R² above 0.92), but also detects adulterations as small as 5%, verifies origin, and enables real-time process monitoring. The case studies from Spain, Argentina, and Uruguay reveal concrete achievements: reduced waste and significantly greater consistency in final products. While the challenge of heterogeneity inherent to meat tissues persists, making universal calibrations difficult, continuous advances in miniaturization, data processing, and integration with automated systems are constantly expanding its field of application, making this technology accessible even to small producers. NIR is emerging as an indispensable tool in a sector where transparency, efficiency, and quality assurance constitute increasingly decisive competitive factors, establishing new analytical standards that respond to the growing demands of both consumers and regulatory agencies.
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    Evaluación de la espectroscopía de infrarrojo cercano NIRS como método secundario para la detección de adulteraciones en aceite de oliva, integrando técnicas de aprendizaje automático: revisión sistemática
    (Universidad Santiago de Cali, 2025) Hernández Díaz, Richard Yesid; Morales Morales, Jimmy (Director)
    Olive oil adulteration has been a recurring problem affecting its authenticity and quality, generating negative impacts on the food industry and consumer confidence. In this study, the effectiveness of nearinfrared spectroscopy (NIRS) as a secondary method for detecting adulterations in olive oil was evaluated, integrating machine learning techniques. To this end, a systematic review was conducted following the PRISMA methodology, selecting articles from indexed databases that addressed the application of NIRS in identifying fraud in edible oils. Various machine learning-based modeling approaches were analyzed, including multivariate regression, discriminant analysis, and neural networks. 3 The results indicated that combining NIRS with machine learning algorithms improved the accuracy and efficiency of adulteration detection compared to traditional analytical methods. In particular, the supervised models were able to identify specific spectral patterns with high sensitivity and specificity. It was concluded that the implementation of NIRS, together with advanced modeling techniques, represents a viable, rapid and economically accessible alternative for the quality control of olive oil, reducing dependence on conventional chromatographic methods.
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    Factores que determinan la calidad de los granos de cacao y uso de la espectroscopia de infrarrojo cercano (NIRS) Como herramienta de Caracterización
    (Universidad Santiago de Cali, 2025) Hurtado Gallo, Alejandra; Ríos Acevedo, Jhon Jairo (Director)
    Currently, the cocoa production industry faces several challenges involving sustainability in both production and marketing, as various factors such as climate, technology, the proliferation of diseases, and lack of investment in improvement programs have created a conflict between demand and annual production. Additionally, the use of costly technologies like high-performance liquid chromatography (HPLC) for analyzing raw materials and finished products has left some small producers uncompetitive in the production chain. Other options, such as near-infrared spectroscopy (NIRS), promise to be a versatile tool with low operational costs and short response times. Furthermore, this technology does not require specialized personnel since analyses can be performed in situ without destroying the sample, which favors the development and competitiveness of small cocoa farmers. Studies in different scientific fields such as chemistry, medicine, and agriculture employ NIRS technology as a source of information for evaluating quality parameters. However, one of the main obstacles of this technique is the need to use standard reference methods for calibration and its low sensitivity when dealing with very small samples, in addition to the complexity of reading its spectra. Nevertheless, this technology relies on chemometric models to predict the quantity of a compound of interest. Additionally, to correct the effect of scattering in the data, vector normalization (SNV) is used, which occurs due to spectral differences in particle size of solid samples, as it minimizes baseline shift variations. The review addressed important topics about the application of near-infrared spectroscopy in cocoa production and how genetic variability influences the results. Moreover, results reported by various researchers show that the main changes in composition are not only related to the variety but also to the geographic area and climatic conditions. It is worth noting that most cocoa varieties correspond to hybrid species and that current studies do not focus on existing clones, since hybridization of cocoa seeds frequently occurs due to incompatible species during pollination. Furthermore, the opportunities and different challenges presented by this technique in agriculture are discussed, not only in cocoa production but also in other grains, with the ultimate goal of providing information on the findings of various authors in determining quality parameters using nearinfrared spectroscopy (NIRS) and its current status as an analytical tool.
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    Review: química forense. Métodos de extracción y detección de sustancias psicoactivas en cabello y uñas"
    (Universidad Santiago de Cali, 2025) Silva Correa, Herlen Dallana; Rios Acevedo, Jhon Jairo (Director)
    The detection of psychoactive substances in keratin matrices such as hair and nails has been a challenge for forensic toxicology due to the need for accurate, sensitive and reproducible methods to identify chronic use or prolonged exposure to drugs. This review aimed to evaluate recent studies on analytical methods employed between 2020 and 2025, with emphasis on improving recovery rate, extraction time and limit of detection (LOD). A systematic review of scientific studies describing extraction and detection techniques applied to keratin matrices was performed. This included comparative analyses of methods such as solid-phase extraction, solid-phase microextraction, ultrasound-assisted extraction and new on-line strategies. Detection technologies such as LCMS/MS, HRMS, GC-MS and biosensors were also evaluated. The results showed a clear trend towards more efficient, sustainable methods with high capacity for multianalyte analysis, as chromatographic techniques coupled to mass spectrometry offered high sensitivity and specificity, while emerging technologies stood out for their speed and portability, although with limitations in sensitivity.
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    Desarrollo de un filtro de carbón activado para la eliminación de ácido cianúrico, subproducto de la desinfección del agua de piscinas
    (Universidad Santiago de Cali, 2025) García Zapata, Nohemy; Ríos Acevedo, Jhon Jairo (Director)
    Currently, public health regulatory bodies are increasingly demanding the disinfection of swimming pool water to prevent disease and avoid a new pandemic. This has led to the use of disinfectants that generate toxic byproducts such as cyanuric acid. To date, in our city, the only way to reduce its concentration is through water disposal, which increases maintenance costs and generates a negative environmental impact. To address this problem, a prototype filter was developed with three types of activated carbon: commercially available for fish tanks, 8x30 granular, and powder, evaluating its efficiency in a pilot pool under controlled conditions. Statistical analysis confirmed that 8x30 granular activated carbon was the most efficient material for removing cyanuric acid, achieving a 28.4% reduction in a single filtration. Furthermore, it presented lower variability and greater precision in the analyzed parameters, supporting its selection as the most suitable filter material for this process. Additionally, this proposal proved to be more economically viable than the traditional method.
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    Obtención de nanoarcillas mediante intercalación de las capas de arcilla bentonítica con el aminoacido l-lisina.
    (Universidad Santiago de Cali, 2025) Arboleda Valencia, Lina María; Ríos Acevedo, Jhon Jairo (Director)
    In the present study, organoclays were obtained from modified bentonite or montmorillonite (MMT) through a lysine intercalation process. Initially, the clay was cleaned and purified by stirring and hydrochloric acid to eliminate any organic components that could interfere with the intercalation process. Subsequently, lysine was intercalated into the clay structure. The material was characterized by Fourier transform infrared spectrophotometry (FTIR), thermogravimetric analysis (TGA), laser diffraction (LD), and scanning electron microscopy (SEM). Additionally, a physicochemical characterization was performed using standardized methodologies taken from the internal methods manual of a non-metallic industrial minerals producer. The results obtained confirmed the intercalation of lysine into montmorillonite (MMT), which demonstrated a significant increase in the swelling capacity of the lysine-MMT product compared to unintercalated MMT.
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    Obtención de ácido peracético mediante un método alternativo basado en bio-blanqueo para lavado y desinfección de prendas hospitalarias
    (Universidad Santiago de Cali, 2025) Tobar Acosta, Valeria; Ortega, Juan David; Ríos Acevedo, Jhon Jairo (Director)
    The availability of Peracetic Acid (APA) in the presence of Hydrogen Peroxide (H₂O₂) was evaluated within an alternative bleaching and disinfection system (Triacetin (Tri)/ H₂O₂ catalyzed by Arylesterase (Ar)) for hospital garments (PUH) of the company Lavaclinicas S.A. For the quantification of APA, the permanganometric/iodometric technique was used. The research was carried out in two scenarios after confirming the positive availability of APA through the action of an enzyme that performs the perhydrolysis reaction. The first scenario consisted of determining the time interval of highest reaction yield, identified between 10 and 15 minutes. The second evaluated the reduction of PCA and DNA stains compared to the currently used system (TAED/ H₂O₂), achieving partial removal of PCA and total removal of DNA. In the first scenario, several experimental systems were designed in which variables such as quantities, pH adjustments, chaotropic agents, and ammonia and phosphate solutions were adjusted to hyperactivate the Ar enzyme. The results indicated that the phosphate solution achieved a maximum efficiency of approximately 60%. In the second scenario, stains were treated with and without the addition of detergent (WITH and WITHOUT, respectively). Although the detergent partially denatures the enzyme and affects the generation of APA, it facilitates bleaching and the removal of difficult-to-remove stains, such as PCA. The latter, produced by chlorhexidine gluconate and sodium hypochlorite, are visually similar to DNA but are significantly more difficult to remove than PUH. The alternative system demonstrated comparable efficiency to the current system. Therefore, it is recommended to add the detergent after the time interval of highest reaction efficiency to avoid interference with APA generation.
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    Identificación de compuestos volátiles por medio de cromatografía de gases acoplada a masas aplicado en la producción de cerveza
    (Universidad Santiago de Cali, 2022) Osorio Rengifo, Juan Fernando; López Parra, Lizbeth Lorena (Directora)
    Volatile compounds were identified in three different beers prepared by using the home brewing technique, which in turn include the formulation of different types of hops. Consequently, analytical techniques were applied to more effectively determine their sensory profile. Likewise, techniques were used to obtain these volatile compounds through a gas chromatograph coupled to a mass spectrometer (GC-MS). The hops samples were: Amarillo, Loral and East Kent Golding's. Structures of some molecules of each sample were obtained. Finally, by means of a survey, the sensory profile was verified by 10 trained panelists. Common profiles with floral and herbal notes were found, as well as specific notes to each sample.
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    Síntesis, caracterización y evaluación antimicrobiana del ligante N-bencil(1,4-fluorbencil) ditiocarbamato coordinado a Co(III)
    (Universidad Santiago de Cali, 2021) Becerra Aguirre, Nalley Alejandra; D'vries Arturo, Richard Fernando (Director); Flórez López, Edwin (Director)
    In this research work, the synthesis and characterization of the secondary amine N-benzyl (1,4-fluorobenzyl) amine was carried out, which was obtained by the condensation of 4-fluorbenzylamine and benzaldehyde. The formation of this was verified by FIT-IR, where the main bands of a secondary amine could be evidenced. It was also characterized by mass spectrometry which confirmed the mass of the molecular ion. In the same way, the in situ synthesis of the Co (III) coordination compound and the N-benzyl (1,4-fluorobenzyl) dithiocarbamate ligand was carried out, using the aforementioned amine and CS2 as precursor. This coordination compound was characterized by different spectroscopic techniques such as: FT-IR, through which it was possible to confirm the bidentate coordination mode for the S-M-S bond, UV-Vis in solution with which it was determined that the compound is field strong, with an octahedral geometry and thermal analysis (TGA-DSC) which allowed to determine the molecular formula of the coordination compound [Co(DTC)3]•(H2O)2. Finally, microbial inhibition tests were carried out, which allowed to know the inhibition capacity of the coordination compound against bacteria of the genus Mycobacterium using the microtiter test with resarzurin. Through the test, it was possible to determine that the compound has low inhibitory activity against bacteria such as M. smegmatis.