Sequential Extraction
Mostrando 1-12 de 103 artigos, teses e dissertações.
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1. PROCESSING OF A METAL CONCENTRATE FROM GROUND WASTE PRINTED CIRCUIT BOARDS IN ACIDIC MEDIA USING HYDROGEN PEROXIDE AS OXIDANT
The recovery of precious and base metals of a metal concentrate from ground waste printed circuit boards (PCBs) is described in detail. Samples were treated with NaOHaq. to remove the soldering mask. Experiments were performed in acidic medium (HF, H2SO4, CH3COOH or H3PO4) using H2O2 as oxidant. Base metals were leached in high yields (>99 wt.%) at ~40 ºC a
Quím. Nova. Publicado em: 20/07/2020
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2. Cichorium intybus from India: GC-MS Profiling, Phenolic Content and in vitro Antioxidant Capacity of Sequential Soxhlet Extracted Roasted Roots
Abstract Research on the bio-activities and chemical composition of roasted C. intybus roots from India is very little. In present studies GC-MS analysis of volatile components of roasted C. intybus roots, phenolics and flavonoid content estimation and antioxidant potential of roasted C. intybus roots was carried out. Antioxidant potential was also evaluate
Braz. arch. biol. technol.. Publicado em: 25/11/2019
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3. Validation of a Standard Operating Procedure (SOP) for Forensic Soils Investigation in Brazil
ABSTRACT Soil traces are useful as forensic evidence due to their potential to transfer and adhere to different types of surfaces on a range of objects or persons. Several works have been developed in forensic soils, under different analytical approaches. However, in Brazil, only the researches from the Group of the Federal University of Paraná have develop
Rev. Bras. Ciênc. Solo. Publicado em: 09/09/2019
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4. SEQUENTIAL PROCESSING OF Psidium guajava L. LEAVES: STEAM DISTILLATION AND SUPERCRITICAL FLUID EXTRACTION
ABSTRACT Extracts from the leaves of Psidium guajava L have been studied due to their importance as a source of natural antioxidant components with possible applications in the pharmaceutical and food industries. In this work, the sequential use of steam distillation and supercritical fluid extraction was studied to obtain the essential oil from the leaves a
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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5. Use of Mixture Design with Minimal Restrictions to Optimize an Extraction Procedure Employing Diluted Acids Assisted by Ultrasound and Microwave for Nutrient Element Determination in Vegetal Samples
In this work, it was developed an alternative analytical strategy for the preparation of vegetal samples extracted with diluted acids and assisted by ultrasound and microwave radiation for the determination of nutrients elements by fast sequential flame atomic absorption spectrometer. The conditions optimized using univariate and multivariate methodologies f
J. Braz. Chem. Soc.. Publicado em: 2018-06
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6. Modelling of Lead Migration from Electronic Waste to Mixtures of Kaolinite, Iron Oxides and Organic Matter
Improper disposal of electronic waste in the environment facilitates migration of heavy metals, especially lead, into the soil and can contribute to the bioavailability of this species. Based on a simplex-centroid mixture experimental design, small-scale tests were performed for incubation of printed circuit boards (PCBs) in mixtures containing organic matte
J. Braz. Chem. Soc.. Publicado em: 2016-05
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7. Nectandra falcifolia: potential phytopharmaceutical for skin damage protection designed by statistical approach and characterized by photoacoustic spectroscopy
AbstractPhytopharmaceutical products are being used in the treatment and prevention of health problems. Nowadays, the development and evaluation of novel pharmaceutical products is expensive and time consuming. A statistical approach is a good tool for optimal development processes. Nectandra falcifolia (Nees) J.A. Castigl. ex Mart. Crov. & Piccinini, Laurac
Rev. bras. farmacogn.. Publicado em: 2015-06
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8. Enamel crystals of mice susceptible or resistant to dental fluorosis: an AFM study
Objective: This study aimed to assess the overall apatite crystals profile in the enamel matrix of mice susceptible (A/J strain) or resistant (129P3/J strain) to dental fluorosis through analyses by atomic force microscopy (AFM). Material and Methods: Samples from the enamel matrix in the early stages of secretion and maturation were obtained from the inc
J. Appl. Oral Sci.. Publicado em: 2014-06
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9. Determination of metal associated with proteins of wheat seed samples after sequential extraction procedure
Este trabalho foi conduzido para estudar a distribuição de Cu, Fe, Mn e Zn nas frações proteicas de amostras de trigo submetidas a um procedimento de extração sequencial. Maiores concentrações dos elementos foram determinadas na fração extraída com tampão Tris-HCl contendo 1% de dodecil sulfato de sódio (SDS). As frações da amostra de trigo ob
J. Braz. Chem. Soc.. Publicado em: 2014-02
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10. Improving the extraction conditions of endoglucanase produced by Aspergillus niger under solid-state fermentation
Production of cellulases under solid-state fermentation (SSF) is a promising technique that can help to reduce costs. Besides optimizing the production process, it is also important to consider enzyme recovery during the extraction step. Here, an experimental design methodology was used to investigate the effects of the operational parameters solid to liquid
Braz. J. Chem. Eng.. Publicado em: 2013-03
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11. Distribuição de Zn, Pb, Ni, Cu, Mn e Fe nas frações do sedimento superficial do Rio Cachoeira na região sul da Bahia, Brasil
The metal distribution in the surface sediment fractions of the Cachoeira River was evaluated based on the fractionation method using a five-step sequential extraction. The determination of metals was made by flame atomic absorption spectrophotometry (F AAS). Zn, Pb and Cu exhibit higher concentrations in the residual fraction of the sediment from sites that
Quím. Nova. Publicado em: 2013
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12. DinÃmica de fÃsforo em manguezais impactados por Ãguas residuÃrias no Estado do CearÃ. / Dynamics of phosphorus in mangroves impacted by the state of CearÃ.
Recent studies demonstrated the efficacy of mangrove retaining nutrients and, in particular, the ability of the mineral component of the buffer in its high soil phosphorus levels. In general, the mangroves have been considered as important sinks of nutrients due to its high capacity purification of effluents. However, depending on the geochemical conditions
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/06/2012