Pub Date : 2024-07-24DOI: 10.52571/ptq.v21.n47.2024_01_juliao_pg_01_09.pdf
Hélcio Silva dos Santos, Lúcia Betânia da Silva Andrade, F. L. Moreira, Felipe Wesley de Vasconcelos Paulino, Danielle Rodrigues Maciel, Murilo S. S. Julião
Background: Ascorbic acid (AA), uric acid (UA), and dopamine (DA) play crucial roles in human metabolism. These substances coexist in biological fluids, and their levels are directly associated with various pathologies. A significant problem encountered in the direct and simultaneous electrochemical detection of AA, UA, and DA is that these species present very close oxidation potentials on most electrode materials, leading to an overlap in the voltammetric response. Aim: The main goal of this work was to determine the concentration of AA, UA, and DA in a natural water sample on a carbon nanotube paste electrode (CNTPE). Methods: All voltammetric measurements were performed on a µAutolab potentiostat/galvanostat (Metrohm) connected to an electrochemical cell of three electrodes: working, reference (Ag/AgCl, KCl3.0M), and auxiliary (platinum). The working electrode was handmade in our laboratory. The following proportions were used to prepare the paste: 50% CNT + 50% mineral oil and 65% CNT + 35% mineral oil. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used for the electroanalytical study. Results: The linear ranges for the simultaneous determination of AA, DA, and UA by DPV were: 0.45 – 1.0 mM, 50 – 200 ?M, and 10 – 90 ?M, respectively. The LODs of the proposed method for AA, DA, and UA were: 7.97 mM; 8.57 ?M, and 5.96 ?M, respectively. The relative standard deviations (RSD) were 4.6, 2.8, and 1.6% for 0.45 mM of AA, 50 ?M of DA, and 50 ?M of UA. Discussion: The oxidation mechanism of: AA, UA, and DA is a process that involves two electrons and 2 protons. Electrochemical detection of DA in the presence of high levels of AA on carbon-based electrodes becomes difficult due to the catalytic oxidation of AA by DA. For the three molecules, AA, UA, and DA, it is observed that the oxidation peak currents increased with increasing concentration. Conclusions: CNTPE allowed the separation of the oxidation peaks of the ternary mixture of AA, UA, and DA by cyclic voltammetry and, when associated with DPV allowed the simultaneous quantitative determination of AA, UA, and DA.
背景：抗坏血酸（AA）、尿酸（UA）和多巴胺（DA）在人体新陈代谢中起着至关重要的作用。这些物质同时存在于生物液体中，其含量与各种病症直接相关。在对 AA、UA 和 DA 进行直接和同步电化学检测时遇到的一个重要问题是，这些物质在大多数电极材料上的氧化电位非常接近，从而导致伏安响应重叠。目的：本研究的主要目的是在碳纳米管浆料电极（CNTPE）上测定天然水样中 AA、UA 和 DA 的浓度。方法：所有伏安测量均在碳纳米管浆料电极上进行：所有伏安测量均在一台 µAutolab 恒电位仪/恒电流仪（Metrohm）上进行，该仪器与一个由三个电极组成的电化学电池相连：工作电极、参比电极（Ag/AgCl，KCl3.0M）和辅助电极（铂）。工作电极是我们实验室手工制作的。浆料的配制比例如下：50% CNT + 50% 矿物油和 65% CNT + 35% 矿物油。电分析研究采用了循环伏安法（CV）和差分脉冲伏安法（DPV）。研究结果DPV 同时测定 AA、DA 和 UA 的线性范围为分别为 0.45 - 1.0 mM、50 - 200 M 和 10 - 90 M。该方法对 AA、DA 和 UA 的检出限分别为 0.45 - 1.0 mM、50 - 200 ?分别为 7.97 mM、8.57 M 和 5.96 M。AA 0.45 mM、DA 50 M 和 UA 50 M 的相对标准偏差（RSD）分别为 4.6%、2.8%和 1.6%。讨论AA、UA 和 DA 的氧化机制AA、UA 和 DA 的氧化机制是一个涉及两个电子和两个质子的过程。由于 DA 对 AA 的催化氧化作用，在碳基电极上对存在高浓度 AA 的 DA 进行电化学检测变得十分困难。对于 AA、UA 和 DA 这三种分子，可以观察到氧化峰电流随着浓度的增加而增加。结论：CNTPE 可通过循环伏安法分离 AA、UA 和 DA 三元混合物的氧化峰，当与 DPV 联用时，可同时定量测定 AA、UA 和 DA。
{"title":"SIMULTANEOUS DETERMINATION OF ASCORBIC ACID, URIC ACID, AND DOPAMINE ON CARBON NANOTUBE PASTE ELECTRODE","authors":"Hélcio Silva dos Santos, Lúcia Betânia da Silva Andrade, F. L. Moreira, Felipe Wesley de Vasconcelos Paulino, Danielle Rodrigues Maciel, Murilo S. S. Julião","doi":"10.52571/ptq.v21.n47.2024_01_juliao_pg_01_09.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v21.n47.2024_01_juliao_pg_01_09.pdf","url":null,"abstract":"Background: Ascorbic acid (AA), uric acid (UA), and dopamine (DA) play crucial roles in human metabolism. These substances coexist in biological fluids, and their levels are directly associated with various pathologies. A significant problem encountered in the direct and simultaneous electrochemical detection of AA, UA, and DA is that these species present very close oxidation potentials on most electrode materials, leading to an overlap in the voltammetric response. Aim: The main goal of this work was to determine the concentration of AA, UA, and DA in a natural water sample on a carbon nanotube paste electrode (CNTPE). Methods: All voltammetric measurements were performed on a µAutolab potentiostat/galvanostat (Metrohm) connected to an electrochemical cell of three electrodes: working, reference (Ag/AgCl, KCl3.0M), and auxiliary (platinum). The working electrode was handmade in our laboratory. The following proportions were used to prepare the paste: 50% CNT + 50% mineral oil and 65% CNT + 35% mineral oil. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used for the electroanalytical study. Results: The linear ranges for the simultaneous determination of AA, DA, and UA by DPV were: 0.45 – 1.0 mM, 50 – 200 ?M, and 10 – 90 ?M, respectively. The LODs of the proposed method for AA, DA, and UA were: 7.97 mM; 8.57 ?M, and 5.96 ?M, respectively. The relative standard deviations (RSD) were 4.6, 2.8, and 1.6% for 0.45 mM of AA, 50 ?M of DA, and 50 ?M of UA. Discussion: The oxidation mechanism of: AA, UA, and DA is a process that involves two electrons and 2 protons. Electrochemical detection of DA in the presence of high levels of AA on carbon-based electrodes becomes difficult due to the catalytic oxidation of AA by DA. For the three molecules, AA, UA, and DA, it is observed that the oxidation peak currents increased with increasing concentration. Conclusions: CNTPE allowed the separation of the oxidation peaks of the ternary mixture of AA, UA, and DA by cyclic voltammetry and, when associated with DPV allowed the simultaneous quantitative determination of AA, UA, and DA.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"61 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141807205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.52571/ptq.v21.n47.2024_05_isaac_pgs_61_68.pdf
Henrique Gonzaga, Éder Fernandes, Isaac Newton Lima da Silva
Background: The speed of a vehicle in a curve can be estimated by analysing yaw marks, which indicate its orientation around the vertical axis. When it exceeds the "critical speed," the vehicle slides laterally, evidenced by the oscillation of the rear tires relative to the front ones. Aim: To present a methodology for reconstructing yaw accidents, with an analysis of uncertainties. Methods: This article uses Monte Carlo simulation software to address uncertainties in determining the critical yaw speed of vehicles. The radius of curvature is calculated considering the chord, average arrow, and vehicle gauge, while the road is characterized by negative superelevation and specific friction coefficient. The simulation models input variables with probabilistic distributions, analysing uncertainties related to road characteristics, vehicle properties, environmental conditions, and measurement errors. Results: The simulation results provide a detailed assessment of the uncertainties involved in determining the critical yaw speed, highlighting the importance of a probabilistic approach to ensure a more realistic and reliable assessment of vehicular safety. Discussion: When evaluating measurement uncertainties, it is essential to consider the sensitivity coefficient to ensure a precise and comprehensive analysis of uncertainty sources. Conclusions: This study highlights the importance of analysing and controlling critical variables, such as the radius of curvature and friction coefficient, to accurately determine the critical yaw speed and ensure reliable vehicular safety measures..
{"title":"ANALYSIS OF UNCERTAINTY IN THE DETERMINATION OF THE CRITICAL YAW RADIUS USING MONTE CARLO SIMULATION","authors":"Henrique Gonzaga, Éder Fernandes, Isaac Newton Lima da Silva","doi":"10.52571/ptq.v21.n47.2024_05_isaac_pgs_61_68.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v21.n47.2024_05_isaac_pgs_61_68.pdf","url":null,"abstract":"Background: The speed of a vehicle in a curve can be estimated by analysing yaw marks, which indicate its orientation around the vertical axis. When it exceeds the \"critical speed,\" the vehicle slides laterally, evidenced by the oscillation of the rear tires relative to the front ones. Aim: To present a methodology for reconstructing yaw accidents, with an analysis of uncertainties. Methods: This article uses Monte Carlo simulation software to address uncertainties in determining the critical yaw speed of vehicles. The radius of curvature is calculated considering the chord, average arrow, and vehicle gauge, while the road is characterized by negative superelevation and specific friction coefficient. The simulation models input variables with probabilistic distributions, analysing uncertainties related to road characteristics, vehicle properties, environmental conditions, and measurement errors. Results: The simulation results provide a detailed assessment of the uncertainties involved in determining the critical yaw speed, highlighting the importance of a probabilistic approach to ensure a more realistic and reliable assessment of vehicular safety. Discussion: When evaluating measurement uncertainties, it is essential to consider the sensitivity coefficient to ensure a precise and comprehensive analysis of uncertainty sources. Conclusions: This study highlights the importance of analysing and controlling critical variables, such as the radius of curvature and friction coefficient, to accurately determine the critical yaw speed and ensure reliable vehicular safety measures..","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"66 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Background: The rising global population and decreasing agricultural land challenge the food supply, worsened by land degradation and water scarcity. Using IoT solutions, precision farming offers promise for addressing these issues by enhancing productivity, profitability, and environmental sustainability. The paper proposes an IoT-based automated monitoring and irrigation system with predictive analysis as a solution. Aims: To develop an IoT-based irrigation model with cloud computing, a mobile app for remote monitoring and irrigation control, and a predictive analysis method for forecasting weather conditions. Methods: IoT sensors are connected to a node MCU, and they monitor real-time temperature, humidity, and soil moisture. A water pump adjusts irrigation accordingly. Data is sent to ThingSpeak for visualization and Firebase for storage and is accessible via a mobile app. Predictive analysis combines sensor and historical weather data using the Random Forest algorithm to optimize irrigation. This determines the ideal irrigation frequency, duration, and timing based on predicted temperature and soil moisture levels, ensuring optimal soil moisture for plant growth. Results: The system exhibited encouraging outcomes. It displayed transformative potential by harnessing IoT, cloud computing, and predictive analytics. Offering precise soil moisture monitoring, instant data access, and tailored advice, the system can elevate crop management, streamline water consumption, and boost productivity among Indian farmers. Discussion: The automated crop monitoring and irrigation system has transformative potential in farming. Some future scope and enhancements may include broadening crop compatibility, integrating satellite data, enhancing pest monitoring, improving connectivity, enriching the mobile app, scaling up through partnerships, and refining the predictive models. Conclusions: The IoT-driven crop monitoring system revolutionizes Indian agriculture by optimizing irrigation and integrating weather forecasts. With mobile app enhancements and future improvements, it promises sustainable farming and empowerment for farmers.
{"title":"AN AUTOMATED CROP MONITORING AND IRRIGATION SYSTEM WITH PREDICTIVE ANALYSIS","authors":"Nilotpal Deka, Devaj Neogi, Atowar-Ul Islam, Sangeeta Borkakoty","doi":"10.52571/ptq.v21.n47.2024_03_atowar_pg_24_41.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v21.n47.2024_03_atowar_pg_24_41.pdf","url":null,"abstract":"Background: The rising global population and decreasing agricultural land challenge the food supply, worsened by land degradation and water scarcity. Using IoT solutions, precision farming offers promise for addressing these issues by enhancing productivity, profitability, and environmental sustainability. The paper proposes an IoT-based automated monitoring and irrigation system with predictive analysis as a solution. Aims: To develop an IoT-based irrigation model with cloud computing, a mobile app for remote monitoring and irrigation control, and a predictive analysis method for forecasting weather conditions. Methods: IoT sensors are connected to a node MCU, and they monitor real-time temperature, humidity, and soil moisture. A water pump adjusts irrigation accordingly. Data is sent to ThingSpeak for visualization and Firebase for storage and is accessible via a mobile app. Predictive analysis combines sensor and historical weather data using the Random Forest algorithm to optimize irrigation. This determines the ideal irrigation frequency, duration, and timing based on predicted temperature and soil moisture levels, ensuring optimal soil moisture for plant growth. Results: The system exhibited encouraging outcomes. It displayed transformative potential by harnessing IoT, cloud computing, and predictive analytics. Offering precise soil moisture monitoring, instant data access, and tailored advice, the system can elevate crop management, streamline water consumption, and boost productivity among Indian farmers. Discussion: The automated crop monitoring and irrigation system has transformative potential in farming. Some future scope and enhancements may include broadening crop compatibility, integrating satellite data, enhancing pest monitoring, improving connectivity, enriching the mobile app, scaling up through partnerships, and refining the predictive models. Conclusions: The IoT-driven crop monitoring system revolutionizes Indian agriculture by optimizing irrigation and integrating weather forecasts. With mobile app enhancements and future improvements, it promises sustainable farming and empowerment for farmers.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"14 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.52571/ptq.v21.n47.2024_06_ribamar_pgs_69_85.pdf
José de Ribamar Oliveira Filho, L. D. De Boni
Background: The interview with Professor José de Ribamar, conducted by Luís de Boni, addresses various aspects of his career and contributions to chemistry in Brazil. The conversation includes his experiences in teaching, research, and university administration, as well as his role as President of the Federal Council of Chemistry (CFQ). Aims: The primary aim of the interview is to highlight Professor Ribamar's achievements and challenges throughout his career, and to explore his views on chemistry and its impact on scientific and educational development in Brazil. Methods: The interview was conducted in a question-and-answer format, allowing Professor Ribamar to share his experiences and insights in a detailed and personal manner. The interview was recorded, transcribed, and is available in both text and video formats. Results: Professor Ribamar detailed his academic and professional journey, including his undergraduate and graduate studies in chemistry, his contributions as a professor at the Federal University of Maranhão (UFMA), and his initiatives as a course coordinator and department head. He also discussed the impact of his research and his vision for the future of chemistry, emphasizing the importance of artificial intelligence and algorithms in predicting chemical models. Discussion: The interview provided a comprehensive overview of Professor Ribamar's contributions to chemistry in Brazil. He emphasized the importance of education and ongoing research for scientific advancement, as well as the need to adapt to new technologies. The discussion also addressed the challenges the scientific community faces and the importance of interdisciplinary collaboration. Conclusion: Professor José Ribamar has significantly promoted and developed chemistry in Brazil in academia and public administration. His career illustrates the importance of dedication to education and research, and his reflections offer valuable lessons for future generations of scientists and educators. The interview serves as a testament to his lasting impact on the scientific community.
背景：Luís de Boni 对 José de Ribamar 教授进行的访谈涉及其职业生涯的各个方面以及对巴西化学的贡献。谈话内容包括他在教学、研究和大学管理方面的经历，以及他作为联邦化学理事会（CFQ）主席所发挥的作用。目的：访谈的主要目的是强调里巴马教授在其职业生涯中取得的成就和面临的挑战，并探讨他对化学的看法及其对巴西科学和教育发展的影响。访谈方法：访谈以问答形式进行，让里巴马教授以详细和个人的方式分享他的经验和见解。访谈已录制、转录，并以文本和视频两种格式提供。访谈结果Ribamar 教授详细介绍了他的学术和职业历程，包括他的化学本科和研究生学业、他在马拉尼昂联邦大学（UFMA）担任教授期间所做的贡献，以及他作为课程协调员和系主任所采取的举措。他还讨论了自己研究的影响和对化学未来的展望，强调了人工智能和算法在预测化学模型方面的重要性。讨论：访谈全面概述了 Ribamar 教授对巴西化学的贡献。他强调了教育和持续研究对科学进步的重要性，以及适应新技术的必要性。讨论还涉及科学界面临的挑战和跨学科合作的重要性。结论：若泽-里巴马教授在学术界和公共管理领域极大地促进和发展了巴西的化学事业。他的职业生涯说明了献身教育和研究的重要性，他的思考为后代科学家和教育工作者提供了宝贵的经验。这篇访谈见证了他对科学界的持久影响。
{"title":"EXPLORING THE CAREER AND CONTRIBUTIONS OF JOSÉ RIBAMAR: AN INTERVIEW WITH THE PRESIDENT OF CFQ","authors":"José de Ribamar Oliveira Filho, L. D. De Boni","doi":"10.52571/ptq.v21.n47.2024_06_ribamar_pgs_69_85.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v21.n47.2024_06_ribamar_pgs_69_85.pdf","url":null,"abstract":"Background: The interview with Professor José de Ribamar, conducted by Luís de Boni, addresses various aspects of his career and contributions to chemistry in Brazil. The conversation includes his experiences in teaching, research, and university administration, as well as his role as President of the Federal Council of Chemistry (CFQ). Aims: The primary aim of the interview is to highlight Professor Ribamar's achievements and challenges throughout his career, and to explore his views on chemistry and its impact on scientific and educational development in Brazil. Methods: The interview was conducted in a question-and-answer format, allowing Professor Ribamar to share his experiences and insights in a detailed and personal manner. The interview was recorded, transcribed, and is available in both text and video formats. Results: Professor Ribamar detailed his academic and professional journey, including his undergraduate and graduate studies in chemistry, his contributions as a professor at the Federal University of Maranhão (UFMA), and his initiatives as a course coordinator and department head. He also discussed the impact of his research and his vision for the future of chemistry, emphasizing the importance of artificial intelligence and algorithms in predicting chemical models. Discussion: The interview provided a comprehensive overview of Professor Ribamar's contributions to chemistry in Brazil. He emphasized the importance of education and ongoing research for scientific advancement, as well as the need to adapt to new technologies. The discussion also addressed the challenges the scientific community faces and the importance of interdisciplinary collaboration. Conclusion: Professor José Ribamar has significantly promoted and developed chemistry in Brazil in academia and public administration. His career illustrates the importance of dedication to education and research, and his reflections offer valuable lessons for future generations of scientists and educators. The interview serves as a testament to his lasting impact on the scientific community.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"52 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141808238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.52571/ptq.v21.n47.2024_02_radhi_pg_10_23.pdf
Ahmed Al-Yasari, I. M. Shaheed, Mariam Radhi Kadhim
Background: In recent decades, substantial progress has been achieved in the field of drug delivery through the creation of controlled-release formulations, leading to significant medical advancements. The primary objective of these controlled release systems is to sustain the desired drug concentration in the bloodstream or specific tissues for an extended duration. One class of nanostructures is polyoxometalates (POMs), which are negatively charged anionic nanoclusters consisting of metal and oxygen atoms. POMs are notable for their ability to be precisely controlled in size and shape. These characteristics, combined with their inherent negative charge, contribute to their stability and make them highly versatile structures. Aim: This study aimed to examine the self-assembly of organic-inorganic hybrids using polyoxometalate (POM) Lindqvist-type hexamolybdate and chitosan to synthesize novel 3D nanostructures. These nanostructures were then investigated for their suitability as nanocarriers for the chemotherapy drug )Temozolomide TMZ(. The release of TMZ from the nanocarrier was studied under various pH conditions. Methods: This study comprises two practical components. The first part focuses on synthesizing hierarchical nanostructures designed to load TMZ drugs. The amount of drug loaded onto the as-prepared nanostructure of POM-Chitosan was determined using High-Performance Liquid Chromatography (HPLC) at various loading times. The second part of the study investigates the release process of the TMZ drug from the hierarchical nanostructures. This release process is examined in two buffer solutions with distinct pH values. Results: The surface characteristics, size, chemical composition, and identity of the nanostructures were confirmed using techniques such as HPLC, FTIR, XRD, SEM, and XPS. The results confirm the successful complexation of chitosan with POM Lindqvist-type hexamolybdate. Discussion: The nanocarriers demonstrated an intriguing pH-dependent release behavior, suggesting their potential application in drug delivery systems. Conclusions: In this study, new nanocarriers of chitosan and POM were successfully prepared and loaded with TMZ (21% loading) via self-assembly for oral drug delivery. The as-prepared nanocarrier form of TMZ was fully characterized via XRD, FTIR, XPS, and SEM. The as-prepared oral form of TMZ showed an excellent pH-dependent release of TMZ, where the release rate at pH 7.4 was considerably faster than at pH 2.8.
{"title":"CHITOSAN / HEXAMOLYBDATE NANOSTRUCTURES FOR ORAL DRUG DELIVERY","authors":"Ahmed Al-Yasari, I. M. Shaheed, Mariam Radhi Kadhim","doi":"10.52571/ptq.v21.n47.2024_02_radhi_pg_10_23.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v21.n47.2024_02_radhi_pg_10_23.pdf","url":null,"abstract":"Background: In recent decades, substantial progress has been achieved in the field of drug delivery through the creation of controlled-release formulations, leading to significant medical advancements. The primary objective of these controlled release systems is to sustain the desired drug concentration in the bloodstream or specific tissues for an extended duration. One class of nanostructures is polyoxometalates (POMs), which are negatively charged anionic nanoclusters consisting of metal and oxygen atoms. POMs are notable for their ability to be precisely controlled in size and shape. These characteristics, combined with their inherent negative charge, contribute to their stability and make them highly versatile structures. Aim: This study aimed to examine the self-assembly of organic-inorganic hybrids using polyoxometalate (POM) Lindqvist-type hexamolybdate and chitosan to synthesize novel 3D nanostructures. These nanostructures were then investigated for their suitability as nanocarriers for the chemotherapy drug )Temozolomide TMZ(. The release of TMZ from the nanocarrier was studied under various pH conditions. Methods: This study comprises two practical components. The first part focuses on synthesizing hierarchical nanostructures designed to load TMZ drugs. The amount of drug loaded onto the as-prepared nanostructure of POM-Chitosan was determined using High-Performance Liquid Chromatography (HPLC) at various loading times. The second part of the study investigates the release process of the TMZ drug from the hierarchical nanostructures. This release process is examined in two buffer solutions with distinct pH values. Results: The surface characteristics, size, chemical composition, and identity of the nanostructures were confirmed using techniques such as HPLC, FTIR, XRD, SEM, and XPS. The results confirm the successful complexation of chitosan with POM Lindqvist-type hexamolybdate. Discussion: The nanocarriers demonstrated an intriguing pH-dependent release behavior, suggesting their potential application in drug delivery systems. Conclusions: In this study, new nanocarriers of chitosan and POM were successfully prepared and loaded with TMZ (21% loading) via self-assembly for oral drug delivery. The as-prepared nanocarrier form of TMZ was fully characterized via XRD, FTIR, XPS, and SEM. The as-prepared oral form of TMZ showed an excellent pH-dependent release of TMZ, where the release rate at pH 7.4 was considerably faster than at pH 2.8.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"39 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.52571/ptq.v21.n47.2024_04_hatem_pg_42_60.pdf
H. H. Mihsen, Alaa F. Hussain, Raghad S. Hatem
Background: Mesoporous materials like MCM-41 silica are highly regarded for their structural features and applications in adsorption and catalysis. This study enhances MCM-41's ability to adsorb cobalt and copper ions by introducing amine and Schiff-base groups, boosting its affinity for these pollutants and aiding in their removal from water solutions. Aims: To prepare MCM-41@NTPE and MCM-41@NTPE-BSAL and use them to adsorb heavy pollutants like cobalt and copper divalent ions from aqueous solutions. Methods: Mesoporous materials (MCM-41@NTPE and MCM-41@NTPE-BSAL) derived from rice husk were used as low-cost adsorbents for the adsorption of Co(II) and Cu(II) ions from aqueous solutions. Uptake experiments were performed to determine adsorption parameters like ion concentration, pH, exposure time, and adsorbent mass. Results: MCM-41@NTPE and MCM-41@NTPE-BSAL were characterized by FT-IR, FESEM-EDX, TEM, N2-adsorption–desorption, XRD,AFM and TGA/DTA. FT-IR confirmed the presence of silanol and siloxane groups. XRD and TEM indicated highly ordered hexagonal arrangements. N2–adsorption–desorption analysis revealed average pore diameters of 42.468 nm and 40.417 nm, total pore volumes of 0.094 cm3g?1 and 0.3384 cm3g?1, and specific surface areas of 8.873 m2g?1 and 37.802 m2g?1 for MCM-41@NTPE and MCM-41@NTPE-BSAL, respectively. TGA showed three mass reduction steps. Adsorption assessment showed pH 6 and 5 were optimal for Co(II) and Cu(II) uptake, respectively, and uptake increased with initial concentration and exposure time. Discussion: XRD confirmed the hexagonal mesoporous structure, while BET analysis displayed amorphous natures. TGA suggested MCM-41@NTPE and MCM-41@NTPE-BSAL have potential for stability, although decomposing between 15-900°C. Electron microscopy revealed ordered hexagonal arrangements. The materials demonstrated high efficacy in extracting copper and cobalt ions from aqueous solutions. Conclusions: Two mesoporous silica materials (MCM-41@NTPE and MCM-41@NTPE-BSAL) were prepared from rice husk by functionalizing MCM-41. Adsorption assessment showed uptake depended on exposure time, pH, initial concentration, and adsorbent mass. MCM-41@NTPE-BSAL exhibited better ion uptake than MCM-41@NTPE.
{"title":"SYNTHESIS OF NEW ADSORBENTS VIA FUNCTIONALIZED MCM-41 FOR THE REMOVAL OF SOME IONS FROM AQUEOUS SOLUTION","authors":"H. H. Mihsen, Alaa F. Hussain, Raghad S. Hatem","doi":"10.52571/ptq.v21.n47.2024_04_hatem_pg_42_60.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v21.n47.2024_04_hatem_pg_42_60.pdf","url":null,"abstract":"Background: Mesoporous materials like MCM-41 silica are highly regarded for their structural features and applications in adsorption and catalysis. This study enhances MCM-41's ability to adsorb cobalt and copper ions by introducing amine and Schiff-base groups, boosting its affinity for these pollutants and aiding in their removal from water solutions. Aims: To prepare MCM-41@NTPE and MCM-41@NTPE-BSAL and use them to adsorb heavy pollutants like cobalt and copper divalent ions from aqueous solutions. Methods: Mesoporous materials (MCM-41@NTPE and MCM-41@NTPE-BSAL) derived from rice husk were used as low-cost adsorbents for the adsorption of Co(II) and Cu(II) ions from aqueous solutions. Uptake experiments were performed to determine adsorption parameters like ion concentration, pH, exposure time, and adsorbent mass. Results: MCM-41@NTPE and MCM-41@NTPE-BSAL were characterized by FT-IR, FESEM-EDX, TEM, N2-adsorption–desorption, XRD,AFM and TGA/DTA. FT-IR confirmed the presence of silanol and siloxane groups. XRD and TEM indicated highly ordered hexagonal arrangements. N2–adsorption–desorption analysis revealed average pore diameters of 42.468 nm and 40.417 nm, total pore volumes of 0.094 cm3g?1 and 0.3384 cm3g?1, and specific surface areas of 8.873 m2g?1 and 37.802 m2g?1 for MCM-41@NTPE and MCM-41@NTPE-BSAL, respectively. TGA showed three mass reduction steps. Adsorption assessment showed pH 6 and 5 were optimal for Co(II) and Cu(II) uptake, respectively, and uptake increased with initial concentration and exposure time. Discussion: XRD confirmed the hexagonal mesoporous structure, while BET analysis displayed amorphous natures. TGA suggested MCM-41@NTPE and MCM-41@NTPE-BSAL have potential for stability, although decomposing between 15-900°C. Electron microscopy revealed ordered hexagonal arrangements. The materials demonstrated high efficacy in extracting copper and cobalt ions from aqueous solutions. Conclusions: Two mesoporous silica materials (MCM-41@NTPE and MCM-41@NTPE-BSAL) were prepared from rice husk by functionalizing MCM-41. Adsorption assessment showed uptake depended on exposure time, pH, initial concentration, and adsorbent mass. MCM-41@NTPE-BSAL exhibited better ion uptake than MCM-41@NTPE.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"4 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141806457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-26DOI: 10.52571/ptq.v20.n45.2023_03_chirinos_pgs_21_29.pdf
Richard Alex Contreras Canchan, Hugo David Chirinos Collantes, Aldo Max Delgado Acevedo, C. Carrera
Background: The advancement of the mining industry implies the generation of acid drainage because operations consume between 2% and 4.5% of water demand. In addition, it is estimated that 50,000 tons of waste will be produced, of which 33% represents wastewater stored in tailings tanks. These effluents contain heavy metals such as Fe and Cu that represent a serious danger to society. Aim: The objective of this study is to evaluate the application of photocatalysis for the removal of Fe and Cu in industrial wastewater. This involves the control of process parameters: the catalyst dose (TiO2), pH, and time (days). Methods: The method used is experimental, controlling the process variables through a factorial design. The process variables were monitored applying the 33 factorial design, that is, 3 factors with 3 levels without repetitions. The tests were conducted under conditions with a catalyst at doses of 1.2 and 3 g/L, pH of 2.5 and 8, and a retention time of 1, 2, and 3 days. Therefore, the combination of the factors resulted in 27 experimental units. Results and Discussion: For the photocatalysis application time, in 2 days there were fewer concentrations of Fe and Cu, reaching 0.02 and 0.09 ppm, respectively. In the case of pH, a value of 8 resulted in lower concentrations of Fe and Cu. The optimal dose of the catalyst was 0.5 g/L of TiO2. The removal efficiency was 99.99% for Fe and 99.97% for Cu. In the factor analysis, it is observed that pH has the greatest influence on the removal of Fe and Cu, followed by the time factor. A strong interaction between the two variables is also observed. Conclusions: In conclusion, it was possible to remove Fe and Cu through the application of photocatalysis in synthetic wastewater. The optimal conditions were: pH 8, application time of 2 days, catalyst dose (TiO2) 0.5 g/L, and a removal efficiency greater than 99.90%. These values were similar to those reported by other authors.
{"title":"USE OF PHOTOCATALYSIS FOR THE REMOVAL OF Fe AND Cu","authors":"Richard Alex Contreras Canchan, Hugo David Chirinos Collantes, Aldo Max Delgado Acevedo, C. Carrera","doi":"10.52571/ptq.v20.n45.2023_03_chirinos_pgs_21_29.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v20.n45.2023_03_chirinos_pgs_21_29.pdf","url":null,"abstract":"Background: The advancement of the mining industry implies the generation of acid drainage because operations consume between 2% and 4.5% of water demand. In addition, it is estimated that 50,000 tons of waste will be produced, of which 33% represents wastewater stored in tailings tanks. These effluents contain heavy metals such as Fe and Cu that represent a serious danger to society. Aim: The objective of this study is to evaluate the application of photocatalysis for the removal of Fe and Cu in industrial wastewater. This involves the control of process parameters: the catalyst dose (TiO2), pH, and time (days). Methods: The method used is experimental, controlling the process variables through a factorial design. The process variables were monitored applying the 33 factorial design, that is, 3 factors with 3 levels without repetitions. The tests were conducted under conditions with a catalyst at doses of 1.2 and 3 g/L, pH of 2.5 and 8, and a retention time of 1, 2, and 3 days. Therefore, the combination of the factors resulted in 27 experimental units. Results and Discussion: For the photocatalysis application time, in 2 days there were fewer concentrations of Fe and Cu, reaching 0.02 and 0.09 ppm, respectively. In the case of pH, a value of 8 resulted in lower concentrations of Fe and Cu. The optimal dose of the catalyst was 0.5 g/L of TiO2. The removal efficiency was 99.99% for Fe and 99.97% for Cu. In the factor analysis, it is observed that pH has the greatest influence on the removal of Fe and Cu, followed by the time factor. A strong interaction between the two variables is also observed. Conclusions: In conclusion, it was possible to remove Fe and Cu through the application of photocatalysis in synthetic wastewater. The optimal conditions were: pH 8, application time of 2 days, catalyst dose (TiO2) 0.5 g/L, and a removal efficiency greater than 99.90%. These values were similar to those reported by other authors.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139235393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-26DOI: 10.52571/ptq.v20.n45.2023_02_noora_pgs_08_20.pdf
Noora Kareem Abdul Hasan, Ahmed Aboud Khalifa
Background: Lipoprotein cholesterol measurements fluctuated across the menstrual cycle, corresponding to rising and declining concentrations of gonadotropins and ovarian steroid hormones levels in young women, whereas premenopausal women and those who inside the menopausal transition characterized by a poor ovarian response to high secretion of gonadotropin leading to low levels of ovarian steroids. Aims: To investigate the lipoprotein cholesterol changes and their interactions with sex steroid hormones during different phases of the menstrual cycle in menstruated young and old (premenopausal) women. Methods: The sample included thirty healthy women (aged 20-45 years) divided into two groups with 15 women /group according to their ages )20-25 years( (40-45 years). Blood samples were collected on the 8th, 16th, and 24th days of the menstrual cycle from both young and old menstruating women to compare the previous parameters between these days for each group and compare these parameters between similar days for the first and second groups. Lipid profile (Total cholesterol (TC), Triglyceride (TG), High density lipoprotein (HDL), Low density lipoprotein (LDL), and Very low density lipoprotein (VLDL) changes be assayed by Bio-Systems Kit components. Statistical analysis was carried out using one-way Analysis of Variance (ANOVA), followed by Duncan's test, and t-tests were used to assess differences between groups. Results: TC and TG levels did not significantly increase on the 8th day of the menstrual cycle, which represents the follicular phase, in comparison with the other days (16th and 24th days). However, LDL level increased significantly (p ? 0.05) on the 8th day compared to the other days. On the other hand, HDL and VLDL levels increased on the 16th day of the menstrual cycle, which represents the ovulatory phase. Discussion: TC, TG, and LDL levels increased during the follicular phase and were accompanied by high levels of FSH and estradiol, leading to a favorable lipid profile, whereas FSH and estradiol are considered regulators of cholesterol biosynthesis and a buffering capacity. HDL and VLDL levels rise during ovulation to meet the requirements of ovulation and ensure successful ovulation. Conclusions: Studying and evaluating changes in the lipid profile according to the menstrual cycle phase of the menstrual cycle represents an important issue in knowing the physiological and healthy woman state and preventing cardiovascular disease incidence.
{"title":"LIPID PROFILE CHANGES DURING DIFFERENT PHASES OF MENSTRUATED YOUNG AND PREMENOPAUSAL WOMEN","authors":"Noora Kareem Abdul Hasan, Ahmed Aboud Khalifa","doi":"10.52571/ptq.v20.n45.2023_02_noora_pgs_08_20.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v20.n45.2023_02_noora_pgs_08_20.pdf","url":null,"abstract":"Background: Lipoprotein cholesterol measurements fluctuated across the menstrual cycle, corresponding to rising and declining concentrations of gonadotropins and ovarian steroid hormones levels in young women, whereas premenopausal women and those who inside the menopausal transition characterized by a poor ovarian response to high secretion of gonadotropin leading to low levels of ovarian steroids. Aims: To investigate the lipoprotein cholesterol changes and their interactions with sex steroid hormones during different phases of the menstrual cycle in menstruated young and old (premenopausal) women. Methods: The sample included thirty healthy women (aged 20-45 years) divided into two groups with 15 women /group according to their ages )20-25 years( (40-45 years). Blood samples were collected on the 8th, 16th, and 24th days of the menstrual cycle from both young and old menstruating women to compare the previous parameters between these days for each group and compare these parameters between similar days for the first and second groups. Lipid profile (Total cholesterol (TC), Triglyceride (TG), High density lipoprotein (HDL), Low density lipoprotein (LDL), and Very low density lipoprotein (VLDL) changes be assayed by Bio-Systems Kit components. Statistical analysis was carried out using one-way Analysis of Variance (ANOVA), followed by Duncan's test, and t-tests were used to assess differences between groups. Results: TC and TG levels did not significantly increase on the 8th day of the menstrual cycle, which represents the follicular phase, in comparison with the other days (16th and 24th days). However, LDL level increased significantly (p ? 0.05) on the 8th day compared to the other days. On the other hand, HDL and VLDL levels increased on the 16th day of the menstrual cycle, which represents the ovulatory phase. Discussion: TC, TG, and LDL levels increased during the follicular phase and were accompanied by high levels of FSH and estradiol, leading to a favorable lipid profile, whereas FSH and estradiol are considered regulators of cholesterol biosynthesis and a buffering capacity. HDL and VLDL levels rise during ovulation to meet the requirements of ovulation and ensure successful ovulation. Conclusions: Studying and evaluating changes in the lipid profile according to the menstrual cycle phase of the menstrual cycle represents an important issue in knowing the physiological and healthy woman state and preventing cardiovascular disease incidence.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139235041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-26DOI: 10.52571/ptq.v20.n45.2023_01_galiassi_pgs_01_07.pdf
Gabriela Regina Rosa Galiassi, Érico Tasso Leite Barros Teixeira, Karine Silva de Oliveira, Matheus Henrique Sacomani Martins, Josias do Espírito Santo Coringa
Background: Clean water is essential for human health and the environment. Removing flakes during water treatment is crucial to eliminating suspended particles and contaminants. Optimum pH plays a key role in the efficiency of flocculation, allowing the formation of larger and denser flocs. Adjusting the pH correctly helps to neutralize the electrical charges of the particles and optimize the interaction between them. This results in more efficient removal of flakes and particles, improving the quality of the treated water. Aim: This study aims to determine the optimal pH for flocculation of water in Rio Cuiabá through the Jar Test. Methods: The Jar Test was used to determine the optimal pH of water flocculation in Rio Cuiabá, located in the city of Cuiabá - MT, Brazil. Water samples were mixed in 6 vials with different doses of coagulant, shaken and observed to identify the most effective dosage and pH. The test was carried out using two different coagulants: aluminum sulfate and polyaluminium chloride (PAC). Results and discussion: For the test with aluminum sulfate, the best pH values were found in flasks 4 to 6, where the pH was between 6.37 and 6.5, since, in these cases, the turbidity was almost null or null. In the case of PAC, the best pH was the neutral one, because at pH equal to 7.16 there was the lowest turbidity. Proper pH adjustment affected the efficiency of coagulation and flocculation, influencing the removal of suspended particles and the quality of treated water. The optimum pH promoted the formation of larger and denser flocs, improving particle removal efficiency. Water turbidity was also influenced by pH, and appropriate adjustments can facilitate particulate removal during coagulation and flocculation processes. Conclusions: The determination of the optimal flocculation pH is crucial to improve the quality of treated water, especially in relation to the removal of suspended particles.
{"title":"DETERMINATION OF THE OPTIMUM pH OF WATER FLOCCULATION IN RIO CUIABÁ THROUGH JAR TEST","authors":"Gabriela Regina Rosa Galiassi, Érico Tasso Leite Barros Teixeira, Karine Silva de Oliveira, Matheus Henrique Sacomani Martins, Josias do Espírito Santo Coringa","doi":"10.52571/ptq.v20.n45.2023_01_galiassi_pgs_01_07.pdf","DOIUrl":"https://doi.org/10.52571/ptq.v20.n45.2023_01_galiassi_pgs_01_07.pdf","url":null,"abstract":"Background: Clean water is essential for human health and the environment. Removing flakes during water treatment is crucial to eliminating suspended particles and contaminants. Optimum pH plays a key role in the efficiency of flocculation, allowing the formation of larger and denser flocs. Adjusting the pH correctly helps to neutralize the electrical charges of the particles and optimize the interaction between them. This results in more efficient removal of flakes and particles, improving the quality of the treated water. Aim: This study aims to determine the optimal pH for flocculation of water in Rio Cuiabá through the Jar Test. Methods: The Jar Test was used to determine the optimal pH of water flocculation in Rio Cuiabá, located in the city of Cuiabá - MT, Brazil. Water samples were mixed in 6 vials with different doses of coagulant, shaken and observed to identify the most effective dosage and pH. The test was carried out using two different coagulants: aluminum sulfate and polyaluminium chloride (PAC). Results and discussion: For the test with aluminum sulfate, the best pH values were found in flasks 4 to 6, where the pH was between 6.37 and 6.5, since, in these cases, the turbidity was almost null or null. In the case of PAC, the best pH was the neutral one, because at pH equal to 7.16 there was the lowest turbidity. Proper pH adjustment affected the efficiency of coagulation and flocculation, influencing the removal of suspended particles and the quality of treated water. The optimum pH promoted the formation of larger and denser flocs, improving particle removal efficiency. Water turbidity was also influenced by pH, and appropriate adjustments can facilitate particulate removal during coagulation and flocculation processes. Conclusions: The determination of the optimal flocculation pH is crucial to improve the quality of treated water, especially in relation to the removal of suspended particles.","PeriodicalId":20040,"journal":{"name":"Periódico Tchê Química","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139235965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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