Journal of the Brazilian Chemical Society最新文献_第10页

Determination of Coumarin in Mikania glomerata Infusions by Square-Wave Voltammetry Using a Boron-Doped Diamond Electrode 掺硼金刚石电极方波伏安法测定薇甘菊注射液中香豆素含量

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220152

Denise Nóbrega, A. Lourenço, D. Fernandes, W. Lyra, E. Moreira, Paulo Henrique Diniz, Mario C U Araujo

引用次数: 0

Development of an Environmentally Friendly Extraction Method Using Smartphone-Based Digital Images for the Determination of Total Sulfonamides in Meat Samples 一种基于智能手机数字图像的环境友好提取方法的开发，用于肉类样品中总磺胺的测定

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220153

Laís Maroubo, W. Melchert

{"title":"Development of an Environmentally Friendly Extraction Method Using Smartphone-Based Digital Images for the Determination of Total Sulfonamides in Meat Samples","authors":"Laís Maroubo, W. Melchert","doi":"10.21577/0103-5053.20220153","DOIUrl":"https://doi.org/10.21577/0103-5053.20220153","url":null,"abstract":"Sulfonamides (SAs) are low-cost synthetic antimicrobials widely used in veterinary and human medicine to treat diseases and prevent infections. However, long periods of exposure to sulfonamides can cause adverse effects such as allergic reactions. This work aims to study dispersive solid-liquid microextraction as an alternative method for extracting total SAs in meat samples. The procedure uses a colorimetric reaction based on the formation of a pink compound (imine salt) to determine total sulfonamides (sulfamethazine, sulfadimethoxine, sulfathiazole) with digital measurements. A linear response was observed between 33-233 μg kg-1 for total sulfonamides, and the coefficient of variation (n = 11; 67 μg kg-1 of total SAs) and the limit of detection were estimated to be 0.63% and 10 μg kg-1, respectively. For a 750 mg meat sample, 0.11 mg of 4-dimethylaminocinnamaldehyde, 2.60 mg of sodium dodecyl sulfate, and 275 μL of 1-butanol were consumed per sample, and consequently, generating only 335 μL of residue. Besides this, addition-recovery tests were performed, resulting in a 71-100% recovery range, indicating the trueness of the proposed method.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68328883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Computation-Guided Support to Experiments by the Exploration of Reaction Mechanisms: Organic Synthesis, Natural Products and Environmental Issues 通过探索反应机理为实验提供计算指导支持：有机合成、天然产物和环境问题

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20230043

Karine de Andrade, José Renato D Fajardo, Caio Leal, J. Carneiro, R. Fiorot

{"title":"Computation-Guided Support to Experiments by the Exploration of Reaction Mechanisms: Organic Synthesis, Natural Products and Environmental Issues","authors":"Karine de Andrade, José Renato D Fajardo, Caio Leal, J. Carneiro, R. Fiorot","doi":"10.21577/0103-5053.20230043","DOIUrl":"https://doi.org/10.21577/0103-5053.20230043","url":null,"abstract":"Humankind has experienced a remarkable development since it began to design and optimize chemical reactions to achieve valuable compounds. The key to accomplish these tasks is the proper understanding of how chemical transformations occur at a molecular level, that is, their reaction mechanisms. Based on a suitable mechanistic proposal, experimentalists choose a given chemical protocol to optimize experimental conditions, design new synthetic routes, and circumvent competing reactions. In this context, computational chemistry has become a valuable ally for mechanistic elucidation. We present herein a review of complementary collaborations between experimentalists and theoretical chemists to rationalize processes at the molecular level, focusing mainly on the fields of organic synthesis, natural product chemistry, and systems with environmental interest. Throughout this review, we highlight the ability of computational evaluations to provide answers to questions raised from experiments in a clear and direct way, indicating to experimentalists alternative paths to help them solve their problems.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68333299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Low Cost Modified Biochars from Peanut Shells for the Removal of Textile Dyes 低成本花生壳改性生物炭脱除纺织染料

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220156

N. Nunes, M. T. Santos, Angela Martins

引用次数: 0

Synthesis and Characterization of Au@MnO2 Nanoparticles as Plasmon Enhanced Spectroscopy Substrates 合成与表征Au@MnO2纳米粒子作为等离子体增强光谱基底

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220146

Gabriela P. Oliveira, T. Neves, L. Peixoto, S. Landi, B. Archanjo, Gustavo F. S. Andrade

引用次数: 0

Use of Iron Ore Tailing as Raw Material for Two Products: Sodium Silicate and Geopolymers 利用铁矿尾矿生产硅酸钠和地质聚合物两种产品

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220149

C. Prates, A. Lima, I. Ferreira, Fabiano G F de Paula, Paula S. Pinto, J. Ardisson, R. Lago, A. Teixeira

引用次数: 0

Facile Methods for the Assembly of Large-Area Perovskite Solar Cells and Mini‑Module: A Step-by-Step Description of Layers Processing 大面积钙钛矿太阳能电池和迷你模块组装的简便方法:层处理的逐步描述

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220148

Francineide Lopes de Araújo, A. Nogueira, J. D. de Freitas

{"title":"Facile Methods for the Assembly of Large-Area Perovskite Solar Cells and Mini‑Module: A Step-by-Step Description of Layers Processing","authors":"Francineide Lopes de Araújo, A. Nogueira, J. D. de Freitas","doi":"10.21577/0103-5053.20220148","DOIUrl":"https://doi.org/10.21577/0103-5053.20220148","url":null,"abstract":"Hybrid organic-inorganic perovskites have attracted interest in photovoltaic applications due to their excellent optoelectronic properties and low-temperature processability. From 2009 to 2021, lab-scale perovskite solar cells (PSC) reached a power conversion efficiency (PCE) of 25.7%, and a PCE of 17.9% for perovskite solar modules with an area of 800 cm2. Here, we present an investigation using three deposition techniques, spin-coating, blade-coating, and spraycoating, to process the charge transport layers and the active layer of perovskite solar cells onto 5 cm × 5 cm sized substrates, with device structure glass/fluorine-doped tin oxide (FTO)/c-TiO2/ meso-TiO2+Perovskite/2,2’,7,7’-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9’-spirobifluorene (spiro-OMeTAD) or poly(3-hexylthiophene) (P3HT)/Au. Large-area PSC achieved an opencircuit voltage of around 1.1 V and PCE of 6%. The power generated was sufficient to start a fan. Furthermore, the connection in series of two large-area PSCs generated a voltage of 1.9 V. Then, we developed a simple method for manufacturing a monolithic perovskite mini-module containing two series-connected PSCs without using laser-scribing processes (usually named P1, P2, and P3 processes). This mini-module delivered a voltage of 1.52 V. Both voltages (1.9 and 1.52 V) were enough to turn on a red (or yellow) light-emitting diode (LED). To our knowledge, this is the first scientific report describing the assembly of a large-area n-i-p perovskite single cell and mini-module in Brazil.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68328512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis of Polycardanol Using BF3.O(C2H5)2 as Initiator: Influence of Polymerization Conditions on Reaction Products 以BF3.O(C2H5)2为引发剂合成聚腰果酚:聚合条件对反应产物的影响

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220155

Maximiliano D. Martins, T. Aversa, C. M. D. da Silva, E. D. da Silva, E. Lucas

{"title":"Synthesis of Polycardanol Using BF3.O(C2H5)2 as Initiator: Influence of Polymerization Conditions on Reaction Products","authors":"Maximiliano D. Martins, T. Aversa, C. M. D. da Silva, E. D. da Silva, E. Lucas","doi":"10.21577/0103-5053.20220155","DOIUrl":"https://doi.org/10.21577/0103-5053.20220155","url":null,"abstract":"Cardanol acts to stabilize asphaltene particles in crude oil, but its derivative polycardanol, synthesized with BF3.O(C2H5)2 as initiator, exhibits divergent behavior, acting as both asphaltenes stabilizer and flocculant. This behavior could be related to structural differences in polycardanol samples. Therefore, in this work, we study the influence of some polymerization conditions (monomer purity, initiator concentration, and reaction time) on the structures and molar masses of the reaction products, and the reaction conversion. The materials were characterized by size‑exclusion chromatography and hydrogen and carbon nuclear magnetic resonance. When reacting with distilled cardanol, the conversion, the molar mass, and the homogeneity of structures increased as increasing initiator concentration in the range tested (1-3% m/m). For both monomers (different purity degrees), when using a lower initiator concentration (1% m/m), the product contained a larger amount of unreacted monomer and different structures were obtained due to the occurrence of rearrangements. The presence of triolefinic molecules in the monomer provoked crosslinked structures for higher initiator concentration (2-3% m/m). This study elucidated the differences among the reaction products of polycardanol.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68328989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Fatty Acid Content and Physicalchemical Properties of Cagaite Seed Oil (Eugenia dysenterica DC) Obtained by Different Extraction Methods 不同提取方法得到的Cagaite籽油脂肪酸含量及理化性质

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220147

R. Rial, T. Merlo, P. Santos, Luiz Felipe Dias Melo, O. D. de Freitas, R. Barbosa, C. E. Nazário, L. H. Viana

引用次数: 0

Sensitive Detection of BRCA1 Gene Based on Target Proximity Induced Quenching of the Fluorescence of Copper Nanoclusters 基于靶邻近诱导铜纳米簇荧光猝灭的BRCA1基因敏感检测

IF 1.4 4区化学

Journal of the Brazilian Chemical Society Pub Date : 2023-05-26 DOI: 10.21577/0103-5053.20220154

Jing Hu, Tong Yang, Zhengjia Li, Bo Xiao, Peng Yu

{"title":"Sensitive Detection of BRCA1 Gene Based on Target Proximity Induced Quenching of the Fluorescence of Copper Nanoclusters","authors":"Jing Hu, Tong Yang, Zhengjia Li, Bo Xiao, Peng Yu","doi":"10.21577/0103-5053.20220154","DOIUrl":"https://doi.org/10.21577/0103-5053.20220154","url":null,"abstract":"The mutations of breast cancer susceptibility gene 1 (BRCA1) play an important role in inherited breast cancers. Thus, the sensitive assay of the BRCA1 gene is extremely important for disease diagnosis and human health. Herein, a fast, sensitive and selective assay technique has been constructed based on fluorescent copper nanoclusters (CuNCs). The CuNCs were successfully formed with poly(AT-TA) double stranded DNA (dsDNA) as template. In the absence of the target, a strong red emission was observed under 365 nm ultraviolet (UV) lamp and a big fluorescence response was obtained. However, in the presence of BRCA1 gene, there was only weak red emission and a low response signal was produced because of the target-proximity induced quenching of the fluorescence of CuNCs. The linear range for the BRCA1 gene assay was 2-600 nM, and the limit of detection was 2 nM. The assay technique showed good selectivity, good stability and satisfactory recoveries for the detection of BRCA1 gene in diluted serum samples. Moreover, by integrating a UV lamp and a smartphone, the fluorescence sensor would be transferred to a microfluidic chip, providing a prospective application in point-of-care for monitoring breast cancer risk.","PeriodicalId":17257,"journal":{"name":"Journal of the Brazilian Chemical Society","volume":"171 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68328940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0