Synthesis of 4-iodopyrazoles: A Brief Review

The selective incorporation of halogen into organic molecules provides a challenge to academic and industrial research. This microreview presents an overview of the available methodologies for the synthesis of 4-iodopyrazoles, valuable precursors for the selective construction of highly functionalized organic molecules of synthetic and biological importance.

Avaliação da espécie vegetal Croton cajucara Benth como inibidor de biocorrosão em aço carbono Aisi 1020

Actually in the oil industry biotechnological approaches represent a challenge. In that, attention to metal structures affected by electrochemical corrosive processes, as well as by the interference of microorganisms (biocorrosion) which affect the kinetics of the environment / metal interface. Regarding to economical and environmental impacts reduction let to the use of natural products as an alternative to toxic synthetic inhibitors. This study aims the employment of green chemistry by evaluating the stem bark extracts (EHC, hydroalcoholic extract) and leaves (ECF, chloroform extract) of plant species Croton cajucara Benth as a corrosion inhibitor. In addition the effectiveness of corrosion inhibition of bioactive trans-clerodane dehydrocrotonin (DCTN) isolated from the stem bark of this Croton was also evaluated. For this purpose, carbon steel AISI 1020 was immersed in saline media (3,5 % NaCl) in the presence and absence of a microorganism recovered from a pipeline oil sample. Corrosion inhibition efficiency and its mechanisms were investigated by linear sweep voltammetry and electrochemical impedance. Culture-dependent and molecular biology techniques were used to characterize and identify bacterial species present in oil samples. The tested natural products EHC, ECF and DCTN (DMSO as solvent) in abiotic environment presented respectively, corrosion inhibition efficiencies of 57.6% (500 ppm), 86.1% (500 ppm) and 54.5% (62.5 ppm). Adsorption phenomena showed that EHC best fit Frumkin isotherm and ECF to Temkin isotherm. EHC extract (250 ppm) dissolved in a polar microemulsion system (MES-EHC) showed significant maximum inhibition efficiency (93.8%) fitting Langmuir isotherm. In the presence of the isolated Pseudomonas sp, EHC and ECF were able to form eco-compatible organic films with anti-corrosive properties

Determination of the chemical oxygen demand (COD) using a copper electrode: a clean alternative method

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A comparative solid state C-13 NMR and thermal study of CO2 capture by amidines PMDBD and DBN

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Application of Factorial Design Experiments to the Development of a Disposable Amperometric DNA Biosensor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A simple and environmentally friendly reflectometric method for the rapid quantitative analysis of captopril in pharmaceutical formulations

This paper describes a simple, environmentally friendly and rapid quantitative spot test procedure for the determination of captopril (CPT) in bulk drug and in pharmaceutical formulations by using diffuse reflectance spectroscopy. The proposed method is based on the reflectance measurements of the orange compound (λ max 490 nm) produced by the spot test reaction between CPT and p-chloranil (CL). Under optimal conditions, calibration curves were obtained for CPT by plotting the optical density of the reflectance signal (A R) vs. the log of the mol L -1 concentration, from 6.91×10 -3 to 1.17×10 -1, with a good coefficient of determination (R 2 = 0.9992). The common excipients used as additives in pharmaceuticals do not interfere in the proposed method. The method was applied to determine CPT in commercial pharmaceutical formulations. The results obtained by the proposed method are compared favorably with those obtained by an official procedure at 95% confidence level. The method validation results showed that the sensitivity and selectivity of the methods were adequated for drug monitoring in industrial quality control laboratories. © 2011 Moment Publication.

Desenvolvimento de método limpo para a determinação de uréia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de sistemas de screening automatizados para determinação de sulfonamidas em mel e procedimento limpo para a quantificação de sulfaquinoxalina em medicamentos veterinários

Pós-graduação em Química - IQ

Determinação de parâmetros de transferência de massa do processo de extração supercrítica

A extração com fluido supercrítico de materiais líquidos e sólidos despertou o interesse para aplicações industriais nas últimas décadas, mais particularmente sob o conceito de química verde e biorrefinarias, portanto é fundamental que se faça uma modelagem desse processo a fim de otimizar as condições operacionais e simular o processo. O objetivo geral deste trabalho consiste na determinação de parâmetros de transferência de massa do processo de extração supercrítica de matriz sólida, empregando o dióxido de carbono como solvente, a partir de dados cinéticos de extração e na avaliação sistemática de cinco modelos matemáticos para descrever as cinéticas de extração dos óleos da polpa e da casca do buriti, do óleo de açaí de da oleoresina de cúrcuma, medidas no Laboratório de Extração Supercrítica, da Faculdade de Engenharia Química (UFPA), a fim de contribuir para o estudo de ampliação de escala e análise de custo de produção. Foram avaliados os modelos de Tan e Liou, Goto et al. (1993), Martinez et al. (2003), Esquível et al. (1999), e Sovová (1994). A modelagem das cinéticas de extração foi realizada utilizando aplicativos computacionais desenvolvidos e validados neste trabalho a partir de diferentes dados experimentais publicados na literatura. Diante de 40 cinéticas medidas com diferentes equipamentos de extração, configurações de leito, tipos de matérias primas, preparo dos materiais, pressão e temperatura e outros parâmetros de processo (com destaque ao rendimento global e a vazão de solvente), foi construído um panorama dos resultados acerca da capacidade dos modelos de transferência de massa em descrever as mais diferentes curvas globais de extração. De forma geral, os modelos de Goto et al. (1993) e Sovová (1994) apresentaram as melhores previsões aos dados experimentais das matérias primas tratadas neste trabalho com menores valores de quadrado, erros relativo, faixa de erro e desvios padrão e valores de R² próximos da unidade.

1,3-propanodiol: produção, aplicações e potencial biotecnológico

1,3-propanediol is a high-value specialty chemical which has many industrial applications. Its main use is the production of the polymer polypropylene terephthalate, a thermoplastic used in the textile and automobile industries. The interest in 1,3-propanediol production from glycerol bio-conversion has increased after the employment of biodiesel by various countries, being produced by chemical synthesis from petroleum intermediates or biotechnologically by microbial fermentation. Glycerol is an abundant low-cost byproduct from biodiesel refineries, and it is the only substrate that can be naturally or enzymatically converted to 1,3-propanediol by microbial fermentation. In this review, information on 1,3-propanediol's importance, production and purification are presented, along with results from recent research on glycerol microbial conversion to 1,3-propanediol. The bio-production of this intermediate compound from glycerol is very attractive both economically and environmentally, since it allows the replacement of fossil fuels by renewable resources.

Desenvolvimento de metodologia analítica ambientalmente mais amigável para a determinação de ureía em atrizes diversas

Pós-graduação em Química - IQ

New biphasic mono-component composite material obtained by partial oxypropylation of bacterial cellulose

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A importância da ciência e tecnologia para o desenvolvimento: um estudo de caso da indústria brasileira de química verde

The objective of the research is to map and analyze the investment, strategies of develop and prospects of green chemical industry in Brazil and show the fundamental importance of basic research and applied research in the development of this industry in recent years. The complementary objectives are: (i) to evaluate the role of the Brazilian government as a catalyst, encouraging the development of green chemistry industry through incentives, subsidies and ease in credit lines; ii) mapping of relationships between companies universities and public research institutes in the field of green chemistry; iii) verification of the strategies in the world stage green chemistry, the course of time; iv) the theoretical issues and national plans, and your practicable; v) continued investment in the area, with the worry of them being affected by any matter cyclical such as the discovery of a large deposit of shale gas in the United States and a technological development of oil extraction in Brazil and vi) the pace of R&D for basic and applied in the country with the passage of time

Cromatografia Verde

Sustainability is the ability of human beings interact with the world, preserving the environment to not compromise the natural resources of future generations. This is the main goal of Green Chemistry, which is based on twelve basic principles. One of its branches, the Green Analytical Chemistry, apply these principles in their techniques, such as Green Chromatography. The aim of this study was to do a brief literature review on some chromatographic techniques (Gas Chromatography, High Performance Liquid Chromatography, High Temperature Liquid Chromatography, Ultra Pressure Liquid Chromatograph, Micro Liquid Chromatography and Super Critical Chromatography) and measure their impact on the environment

Inserção de conceitos de química verde nos componentes curriculares de laboratório de química geral

Purpose of this monograph is a critical review of articles and publications worldwide. The insertion of green chemistry concepts in the curriculum components of general chemistry lab, plays a fundamental role in the early years of a Chemistry course towards early embed the philosophy of green chemistry. The fundamental concepts of green chemistry are highlighted in order to present the huge number of challenges in developing new chemistry l in research, industry and education. The practice of a chemical that takes into account ethical environmental attitudes thought since the formation of professionals, may lead to adoption of technical microscale, replacement of toxic agents, reduction of waste generation, etc. who snore a lot with the concept of sustainability