•Journal•ISSN: 0100-4042
Química Nova
Brazilian Chemical Society
About: Química Nova is an academic journal published by Brazilian Chemical Society. The journal publishes majorly in the area(s): Catalysis & Chemistry. It has an ISSN identifier of 0100-4042. It is also open access. Over the lifetime, 5956 publications have been published receiving 89559 citations. The journal is also known as: Química Nova.
Topics: Catalysis, Chemistry, Adsorption, Aqueous solution, Detection limit
Papers published on a yearly basis
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TL;DR: In this paper, the main aspects of validation in chromatographic and electrophoretic analysis, showing similarities and differences between the guidelines established by the different Brazilian and international regulatory agencies.
Abstract: The validation of an analytical method is fundamental to implementing a quality control system in any analytical laboratory. As the separation techniques, GC, HPLC and CE, are often the principal tools used in such determinations, procedure validation is a necessity. The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing, in a general way, the similarities and differences between the guidelines established by the different Brazilian and international regulatory agencies.
900 citations
TL;DR: The main environmental factors that can streamline or alter the production or concentration of secondary metabolites in plants are reviewed.
Abstract: Since secondary metabolites represent a chemical interface between plants and surrounding environment, their syntheses are frequently affected by environmental conditions. Thus, variations in the total content and/or of the relative proportions of secondary metabolites in plants can take place. We review the main environmental factors that can streamline or alter the production or concentration of secondary metabolites in plants. How seasonality, circadian rhythm, developmental stage and age, temperature, water availability, UV radiation, soil nutrients, altitude, atmospheric composition and tissue damage influence secondary metabolism are discussed.
767 citations
TL;DR: A review of the most important pretreatment methods developed to date to enhance the conversion of lignocellulosics is presented in this article, where steam explosion, which precludes the treatment of biomass with high-pressure steam under optimal conditions, is presented as the pretreatment method of choice.
Abstract: Pretreatment of lignocellulosic materials is essential for bioconversion because of the various physical and chemical barriers that greatly inhibit their susceptibility to bioprocesses such as hydrolysis and fermentation. The aim of this article is to review some of the most important pretreatment methods developed to date to enhance the conversion of lignocellulosics. Steam explosion, which precludes the treatment of biomass with high-pressure steam under optimal conditions, is presented as the pretreatment method of choice and its mode of action on lignocellulosics is discussed. The optimal pretreatment conditions for a given plant biomass are defined as those in which the best substrate for hydrolysis is obtained with the least amount of soluble sugars lost to side reactions such as dehydration. Therefore, pretreatment optimization results from a compromise between two opposite trends because hemicellulose recovery in acid hydrolysates can only be maximized at lower pretreatment severities, whereas the development of substrate accessibility requires more drastic pretreatment conditions in which sugar losses are inevitable. To account for this heterogeneity, the importance of several process-oriented parameters is discussed in detail, such as the pretreatment temperature, residence time into the steam reactor, use of an acid catalyst, susceptibility of the pretreated biomass to bioconversion, and process design.
576 citations
TL;DR: The chemical composition and pharmacological properties of the very efficient medicinal plant Croton cajucara were investigated according to ethnopharmacological approaches and proved to be both efficient and successful.
Abstract: This paper presents a program emphasizing ethnopharmacological approaches that could allow great success in the study of medicinal plants. The minimum ethnopharmacological research team should consist of a botanist, a chemist and a pharmacologist with each carrying the responsibility for answering in sequential fashion critical questions. The chemical composition and pharmacological properties of the very efficient medicinal plant Croton cajucara were investigated according to ethnopharmacological approaches. The study with this Croton proved to be both efficient and successful. This happy situation was only possible because a multidisciplinary team was involved getting the research done correctly. The ethnopharmacological study involving one other especies Copaifera will be cited.
560 citations
TL;DR: The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing the similarities and differences between the guidelines established by the different Brazilian and international regulatory agencies.
Abstract: The validation of an analytical method is fundamental to implementing a quality control system in any analytical laboratory. As the separation techniques, GC, HPLC and CE, are often the principal tools used in such determinations, procedure validation is a necessity. The objective of this review is to describe the main aspects of validation in chromatographic and electrophoretic analysis, showing, in a general way, the similarities and differences between the guidelines established by the different Brazilian and international regulatory agencies.
507 citations