Vânia Gomes Zuin

Fast supercritical fluid extraction and high-resolution gas chromatography with electron-capture and flame photometric detection for multiresidue screening of organochlorine and organophosphorus pesticides in Brazil’s medicinal plants

A description is given of a rapid and environmentally friendly method to determine organochlorine and organophosphorus pesticide multiresidues--malathion, methidathion, fenitrothion, fenthion, parathion-ethyl, parathion-methyl, lindane, hexachlorobenzene, chlorothalonil, tetradifon, alpha-endosulfan, beta-endosulfan and dieldrin-in Passiflora alata Dryander and pasiflora edulis Sims. f. flavicarpa Deg. leaves by supercritical fluid extraction and high-resolution gas chromatography with electron-capture and flame photometric detection (HRGC-ECD/FPD). The mild extraction conditions [pure CO2; 100 bar (1 bar = 10(5) Pa) and 40 degrees C (p = 0.62 g/ml); 5 min static+10 min dynamic extraction time; ODS trap and elution with 1 ml n-hexane at 2 ml/min] allow for direct analysis by HRGC-ECD/FPD with no prior cleaning procedure. The method provides. in accordance with the validation criteria of the European Pharmacopoeia, analytical results that are similar or even better than the official procedures, and is simpler, faster and cheaper. Mean recoveries of 69.8-107.1% were obtained, with 1.4-14.7% reproducibility (RSD). The method was applied to analyse commercial samples of Passiflora L. from Brazil. Twenty-three percent of the samples showed the presence of the organochlorine or organophosphorus pesticide residue investigated.

Maracujá: um alimento funcional?

Este artigo e uma revisao bibliografica sobre as especies brasileiras de Passiflora (Passiflora edulis fo. flavicarpa O. Deg., P. alata Curtis e P. edulis fo. edulis). A maioria dos artigos da literatura focaliza somente as folhas de Passiflora, enquanto que esta revisao contem informacoes sobre a polpa, cascas e sementes dos frutos do maracuja, com destaque para a composicao quimica, estudos nutricionais e farmacologicos. O enfoque nos frutos do maracuja fundamenta-se no amplo consumo do suco de maracuja (fresco ou industrializado) no Brasil e tambem nas investigacoes em andamento para avaliar o seu potencial uso como alimento funcional.

Determination of Pentachlorophenol and Hexachlorobenzene in Natural Waters Affected by Industrial Chemical Residues

Este trabalho teve como principal objetivo o desenvolvimento de uma metodologia para a analise simultânea de pentaclorofenol (PCP) e hexaclorobenzeno (HCB) em agua natural de subsuperficie proveniente de uma regiao afetada por residuos industriais (Sao Vicente-SP), onde a maior parte da populacao se utiliza de pocos pouco profundos para o abastecimento. A extracao liquido-liquido apresentou bons resultados quanto a recuperacao e repetibilidade do metodo. Para o nivel de fortificacao de 10 ng L-1 de PCP e HCB a recuperacao situou-se entre 81.5% e 103.0%, com um desvio padrao relativo de 2.4% a 4.1%. A determinacao dos analitos foi efetuada por GC-ECD e/ou GC-MS. Adicionalmente, o limite de quantificacao do metodo foi de 5 ng L-1 para PCP e 2 ng L-1 para HCB, valores que estao abaixo do nivel maximo permitido pelas diretrizes da Comunidade Europeia para residuos de pesticidas em agua potavel.

Green chemistry, sustainable agriculture and processing systems: a Brazilian overview

There is a pressing need for renewable and optimal use of resources towards sustainable primary production and processing systems worldwide. Current technologies for food and feedstock production are held accountable for several environmental problems, such as for instance soil and water contamination due to the use of hazardous substances, generation of toxic products and even excess of biomass that is considered waste. To minimize or solve these questions in order to produce an adequate quantity of reliable and healthy food, fibers and other products and energy, new paradigms focusing on sustainable agriculture, bio-based industries or biorefineries have emerged over the last decades. Biorefineries integrate sustainable and environmentally friendly concepts of Green Chemistry with intelligent and integrated farming processes, optimizing the agricultural production. Thermochemical and biochemical processes are excellent alternatives for the production of new classes of renewable biofuels and feedstock, showing relatively small impact on greenhouse gas emissions and important pathways to obtain platform chemicals. This review discusses the current and incipient technological developments for using biomass to generate bio-based chemicals over the last decade, focusing on Green Chemistry concepts towards sustainable agriculture and processing models in Brazil.

Green chemistry in Brazil

The philosophy of green chemistry has been very well received in Latin America’s research and development programs. In this review we describe the green chemistry contributions of Brazilian research groups over the last three years.

Use of Lignins from Sugarcane Bagasse for Assembling Microparticles Loaded with Azadirachta indica Extracts for Use as Neem-Based Organic Insecticides

Microcapsules of sugarcane bagasse lignin loaded with organic extracts of neem (Azadirachta indica) were prepared and evaluated as potential bioinsecticides. Lignins were extracted and modified by oxidation and acetylation reactions providing different biopolymers. Afterwards, they were characterized through several analytical techniques. The formulations were initially prepared as colloidal suspension of lignin nanoparticles, which were then spray-dried. The products were submitted to quality control protocols using high performance liquid chromatography (HPLC), thermal and photochemical degradation studies, followed by biological assays against Spodoptera frugiperda and Diatraea saccharalis. The formulations showed increases in both thermal and photo stability of approximately 40% compared with control samples. All the formulated microparticles were efficient against the insects evaluated and required a shorter time to achieve 100% mortality than the controls. The use of sugarcane bagasse lignins to prepare microparticles improved the resistance of neem extracts against abiotic factors, retaining the biological activity of this biopesticide.

Green sample preparation of complex matrices: towards sustainable separations of organic compounds based on the biorefinery concept

Abstract The development and application of green analytical techniques aiming at the sample preparation of complex matrices for the study of organic compounds have been growing considerably over the last 15 years. Miniaturisation, automation and solventless techniques are gaining importance in this field, associated to others, as is the case of metrics. However, the unreflected use of the so-called green analytical techniques “might lead to doing the same things better, rather than rethinking solutions altogether”. Some limits and potentialities of the green sample preparation towards sustainable separations of organic compounds using the biorefinery concept will be also discussed in this paper, a promising biobased route that can integrate sustainable extraction and purification processes in a whole complete circular unity.

Worldwide trends in green chemistry education

The Interface Between Provision of Information and Behaviour Patterns Education for Sustainable Development and Chemistry Education Rio+20 Sustainable Development Goals (SDGs) and Green Chemistry Green Chemistry in Response to Environmental Issues: Socio-scientific Dilemmas in Science Education Green Chemistry in Brazil: Contemporary Tendencies and Challenges and its Reflections on High School Level Collaborative Development of a Green High School Chemistry Curriculum in Thailand Green Chemistry as a Guiding Idea for Innovation in the Informal Student Laboratory Small Scale Green Chemistry in Higher Education in Thailand Teaching Catalyst Mechanisms for Converting Biomass into Liquid Fuels Holistic Green Chemistry Metrics for use in Teaching Laboratories Embedding Toxicology into the Chemistry Curriculum the State of Green Chemistry Instruction at Canadian Universities Education in Green Chemistry: Incorporating Green Chemistry in Chemistry Teaching Methods Course at the Universiti Sains Malaysia Educational Efforts in Green and Sustainable Chemistry from the Spanish Network in Sustainable Chemistry Green Chemistry and Sustainable Industrial Technology: 10 Years of an MSc Program Introducing Green Chemistry (from a Brazilian Perspective) into Graduate Courses.

Professores, tecnologias digitais e a distração concentrada

Os estudos das influencias das novas tecnologias, presentes tanto na formacao docente quanto em sua pratica, tem sido objeto de muitas pesquisas na area de educacao. Diante desse quadro, tem-se como objetivo investigar o modo como as novas tecnologias modificam a pratica docente, principalmente no contexto atual em que predomina a chamada distracao concentrada nos processos de ensino e aprendizagem. Parte-se do pressuposto de que refletir sobre as relacoes entre tais tecnologias, os professores e os processos de ensino e aprendizagem implica considerar a redefinicao imagetica do professor, bem como dos metodos historicamente empregados para promover a disciplina e a concentracao entre os estudantes.

Use of the Concept of "Bildung" in the International Science Education Literature, Its Potential, and Implications for Teaching and Learning.

Abstract Bildung is a complex educational concept that emerged in Germany in the mid eighteenth century. Especially in Germany and Scandinavia conceptions of Bildung became the general philosophical framework to guide both formal and informal education. Bildung concerns the whole range of education from setting educational objectives in general towards its particular operation in different school subjects, among them science education. In more recent years, the concept of Bildung has slowly begun to be used in the international science and environmental education literature. This paper presents a systematic analysis of the international literature concerning the use of the concept of Bildung, with a view on its meaning in and for science education. At least five versions based on or closely connected to the tradition of Bildung can be identified: (a) Von Humboldt’s classical Bildung, (b) Anglo-American liberal education, (c) Scandinavian folk-Bildung, (d) democratic education, and (e) critical-hermeneutic Bildung. These different understandings of Bildung are discussed in relation to their historical roots, educational theory, critique, and their relation to philosophies of science education, such as different visions of scientific literacy. Based on critical-hermeneutic Bildung, the paper theoretically develops views of critical-reflexive Bildung as an educational metatheory. It is connected to ideas of transformative learning, sustainability education and a Vision III of scientific literacy. Finally, some implications of critical-reflexive Bildung for teaching and learning are discussed.