Journal of laboratory chemical education最新文献

Sustainable Fuels for High School Students: Synthesis of Biodiesel from an Amazon Region Oil (Babassu) 面向高中学生的可持续燃料:从亚马逊地区的石油合成生物柴油(Babassu)

Journal of laboratory chemical education Pub Date : 2023-02-07 DOI: 10.5923/j.jlce.20231101.01

Omar A. El Seoud, Nicolas Keppeler, Maria Helena Zambelli

引用次数: 0

Distance Teaching of the Undergraduate Laboratory During Pandemic Time: Dissolution of Cellulose in Mixtures of Ionic Liquids and Dimethyl Sulfoxide and Biopolymer Regeneration as Films 大流行时期本科实验室远程教学:离子液体与二甲亚砜混合物中纤维素的溶解与生物聚合物再生膜

Journal of laboratory chemical education Pub Date : 2021-10-22 DOI: 10.5923/j.jlce.20210903.02

Nicolas Keppeler, Matheus Costa Lourenço, Omar A. El Seoud

引用次数: 0

A 3D-Printed Higher-Throughput NMR Tube Cleaner 3d打印高通量核磁共振管清洁器

Journal of laboratory chemical education Pub Date : 2021-10-14 DOI: 10.5923/j.jlce.20210903.01

Dana A. Wong, Sibo Lin

引用次数: 0

Education for Sustainable Development: An Undergraduate Chemistry Project on Cellulose Dissolution, Regeneration, and Chemical Recycling of Polycotton 可持续发展教育:一项关于纤维素溶解、再生和化学再循环的本科化学项目

Journal of laboratory chemical education Pub Date : 2020-12-31 DOI: 10.5923/j.jlce.20200801.03

O. A. Seoud, Nicolas Keppeler

{"title":"Education for Sustainable Development: An Undergraduate Chemistry Project on Cellulose Dissolution, Regeneration, and Chemical Recycling of Polycotton","authors":"O. A. Seoud, Nicolas Keppeler","doi":"10.5923/j.jlce.20200801.03","DOIUrl":"https://doi.org/10.5923/j.jlce.20200801.03","url":null,"abstract":"We introduced an undergraduate chemistry project within the framework of education for sustainable development (ESD). The objective of the first part was to demonstrate the efficiency of an ionic liquid (IL)- 1-(n-butyl)-3-methylimidazolium acetate (BuMeImAcO)- as solvent for the dissolution, and subsequent regeneration of cellulose as fiber. Under mechanical stirring, the students dissolved microcrystalline cellulose in a mixture of BuMeImAcO-dimethyl sulfoxide (DMSO) at 80°C. Subsequently, they dyed the dissolved cellulose with a reactive dye, and regenerated (pink) colored fibers by injecting the resulting biopolymer solution into water (a non-solvent for cellulose). The objective of the second experiment was to show the potential application of BuMeImAcO-DMSO for the chemical recycling of the cellulosic component of polycotton (cellulose: polyethylene terephthalate; PET). Cellulose dissolves under the above-mentioned experimental conditions, leaving a mat of PET. The students dyed the dissolved cellulose, and then regenerated the biopolymer as fiber. This project fits the following aspects of ESD: fiber production from renewable sources other than cotton (wood-based cellulose); recycling of cellulose from its blends with synthetic polymers, when their reuse is not feasible. We recommend this project for senior science students of, e.g., chemistry, engineering and pharmacy, because of its simplicity, safety and socioeconomic relevance.","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90901812","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}

引用次数: 2

Application of Chemometrics and Tandem Techniques in the Chemistry of Beverages: Analysis of Methylxanthines in Guaraná Powder Extract 化学计量学和串联技术在饮料化学中的应用:瓜拉<e:1>粉提取物中甲基黄嘌呤的分析

Journal of laboratory chemical education Pub Date : 2020-09-15 DOI: 10.5923/j.jlce.20200802.03

O. A. Seoud, L. Novaki, Nicolas Keppeler, A. M. Chinelatto, S. S. Santos, Vânia Silva

{"title":"Application of Chemometrics and Tandem Techniques in the Chemistry of Beverages: Analysis of Methylxanthines in Guaraná Powder Extract","authors":"O. A. Seoud, L. Novaki, Nicolas Keppeler, A. M. Chinelatto, S. S. Santos, Vânia Silva","doi":"10.5923/j.jlce.20200802.03","DOIUrl":"https://doi.org/10.5923/j.jlce.20200802.03","url":null,"abstract":"Guarana is a tropical fruit that grows in the Amazon basin and the northeastern part of Brazil, from which a popular soft drink is manufactured. The main methylxanthine (MX) in the guarana powder is caffeine (CF); theobromine (TB) and theophylline (TP) are also present in much lower concentrations. Because of the popularity of this soft drink, and the stimulating effects of MXs, we introduced an undergraduate chemistry project on their extraction from guarana powder and subsequent analysis. A literature survey showed that there is some variation in the values of λmax and emax of the three MXs. Using purified authentic samples, we showed that values of λmax and emax of CF, TB and TP are very close. Consequently, their concentrations in guarana extract cannot be calculated using a single technique (UV-Vis). After discussing this problem with the students, the following project was carried out: (i) guarana powder was extracted with acidified aqueous ethanol under different experimental conditions (alcohol volume fraction in the binary solvent mixture, ; powder extraction time, t); (ii) the apparent CF concentration was calculated from the absorbance of the extract at λmax = 272.5 nm; (iii) the extracts were analyzed by high performance liquid chromatography; the three MXs were identified in the chromatograms using internal standards, and the true [CF] calculated. Stage (i) involved use of chemometrics to optimize powder extraction, and to get information on the relative importance of the experimental variables ( is more important than t). Stage (ii) was a straightforward application of Beer’s law. Stage (iii) demonstrated the power of using tandem techniques to solve complex, everyday situation, namely the separation and analysis of biologically active components in consumer products (soft- and energy drinks).","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85336438","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}

引用次数: 0

Light up My Life: An Active Learning Lab to Elucidate Conductive Properties of Electrolytes. 点亮我的生活:阐明电解质导电特性的主动学习实验室。

Journal of laboratory chemical education Pub Date : 2019-01-01

Christina Lee, Nay Chi P Naing, Daisy Herrera, Gerardo Aguirre, Brandon Rodriguez, Jared Ashcroft

引用次数: 0

The Chemistry of Beverages for High School Students: A Project on Extraction and Analysis of Caffeine from Guaraná Powder 高中生饮料的化学成分:瓜拉<e:1>粉中咖啡因的提取与分析项目

Journal of laboratory chemical education Pub Date : 2018-12-31 DOI: 10.5923/j.jlce.20180601.03

O. A. Seoud, L. Novaki, S. Possidonio, A. M. Chinelatto, Maria J. L. d’Almeida e Silva, Paula P. Brotero

{"title":"The Chemistry of Beverages for High School Students: A Project on Extraction and Analysis of Caffeine from Guaraná Powder","authors":"O. A. Seoud, L. Novaki, S. Possidonio, A. M. Chinelatto, Maria J. L. d’Almeida e Silva, Paula P. Brotero","doi":"10.5923/j.jlce.20180601.03","DOIUrl":"https://doi.org/10.5923/j.jlce.20180601.03","url":null,"abstract":"Among soft drinks commercialized in Brazil, the one from guarana seeds (Paullinia cupana) is very popular, ranking second in volume of consumption. Guarana has the highest caffeine concentration in plants; its extraction with chloroform from aqueous solution is feasible using a relatively simple experimental protocol. Because of the commercial importance of this soft drink, and the health-related aspect of (stimulant) caffeine, we developed a project for high-school students on the extraction and analysis of caffeine from guarana powder. In this three-step project, the students did- in their school- a literature survey on the presence of caffeine in beverages, foods and other consumer products. In the second step, they visited the laboratories of the Institute of Chemistry of the University of Sao Paulo (ChemUSP) where they extracted caffeine with CHCl3 from the aqueous solution obtained by treatment of guarana powder with HCl, followed by filtration and alkalization. Using melting point and thin-layer chromatography, they checked the purity of the isolated caffeine. Finally, they determined its concentration by Uv-Vis spectroscopy. We used this simple, safe and low cost experiment to discuss several important concepts, e.g., acids and bases, solvent extraction, purity determination by simple physical method, and quantitative analysis by spectroscopy. The students evaluated this project positively.","PeriodicalId":91121,"journal":{"name":"Journal of laboratory chemical education","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80116739","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}

引用次数: 2

Kinetic Studies of Fenton Oxidation Reaction by UV-VIS Spectroscopy 紫外可见光谱法研究Fenton氧化反应动力学

Journal of laboratory chemical education Pub Date : 2018-08-01 DOI: 10.5923/J.JLCE.20180605.01

Zhongde Dai, Gøril Flatberg, H. Preisig, Liyuan Deng

引用次数: 3

Cultivating Mars: A Project-Based Learning Lab Analyzing an Oxygen Based Redox Reaction in Order to Design an Oxygen-Rich Environment on the Red Planet. 培育火星:基于项目的学习实验室分析基于氧的氧化还原反应，以设计一个红色星球上的富氧环境。

Journal of laboratory chemical education Pub Date : 2018-01-01

Jared M Ashcroft, Ashley Min, Isabel Bojanini, Melanie Hacopian, Kristine Schroeder, Atilla O Cakmak, Brandon Rodriguez

引用次数: 0

An Undergraduate Project “For all Seasons”: The pH-Independent Hydrolysis of bis(2,4-dinitrophenyl) Carbonate in Aqueous Solvents 本科课题“四季适用”:双(2,4-二硝基苯)碳酸酯在水溶液中不依赖ph的水解

Journal of laboratory chemical education Pub Date : 2015-12-31 DOI: 10.5923/j.jlce.20150301.01

O. A. Seoud, P. A. R. Pires, Edgar O. Moraes, J. Pedrotti, H. Nawaz

引用次数: 0