Artigo Publicado em Periódico (Química): Envíos recientes

Mostrando ítems 1-20 de 835

Página siguiente

Synthesis of CdS nano-spheres by a simple and fast sonochemical method at room temperature

Lopes, Paula Aparecida Lima; Santos, Maurício Brandão; Mascarenhas, Artur José Santos; Silva, Luciana Almeida (2014)

Nano-spheres of hexagonal CdS were prepared by a sonochemical method using CdCl2 and Na2S2O3 as precursors, with different molar ratios of cadmium and sulfur in starting solutions, in ethylene glycol and cetyltrimethylammonium ...
Investigation of spectral interferences in the determination of lead in fertilizers and limestone samples using high-resolution continuum source graphite furnace atomic absorption spectrometry

Borges, Aline Rocha; Becker, Emilene M.; François, Luciane L.; Jesus, Alexandre de; Valea, Maria Goreti R.; Welz, Bernhard; Dessuy, Morgana B.; Andrade, Jailson Bittencourt de (2014)

In the present work, spectral interferences on the determination of lead in fertilizer and limestone samples were investigated using high-resolution continuum source graphite furnace atomic absorption spectrometry at the ...
Strontium mono-chloride — A new molecule for the determination of chlorine using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

Pereira, Éderson R.; Welz, Bernhard; Lopez, Alfredo H. D.; Gois, Jefferson S. de; Caramori, Giovanni Finoto; Borges, Daniel L. G.; Carasek, Eduardo; Andrade, Jailson Bittencourt de (Brasil, 2014)

A new method has been developed for the determination of chlorine in biological reference materials using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) of the strontium ...
Influence of Temperature and Time of Seed Aging on the Properties of Beta Zeolite/MCM-41 Materials

T. F, Grecco Saulo; Ernesto, Urquieta González A.; Patrício, Reyes; Marcelo, Oportus; Carmo, Rangel Maria do (Brasil, 2014)

The diffusion restrictions of the reactants caused by the micropores limit the use of zeolites for processing heavy molecules. This demands the development of materials that combine the properties of zeolites and mesoporous ...
Slurry Sampling and HG AFS for the Determination of Total Arsenic in Rice Samples

Santos, Walter Nei Lopes dos; Cavalcante, Dannuza D.; Macedo, Samuel Marques; Nogueira, Jéssica S.; Silva, Erik Galvão Paranhos da (2013)

This paper proposes a procedure for the determination of total arsenic in rice using slurry sampling and hydride generation atomic fluorescence spectrometry (HG AFS). During optimization, water, hydrochloric acid, and ...
Geographical Characterization of Beans Based on Trace Elements After Microwave-Assisted Digestion Using Diluted Nitric Acid

Santos, Wagna Piler Carvalho dos; Santos, Daniele Cristina Muniz Batista; Fernandes, Andréa Pires; Castro, Jacira Teixeira; Korn, Maria das Graças Andrade (2013)

In this paper, multivariate optimization was applied for the development of microwave-assisted digestion using diluted nitric acid for the determination of essential (Ca, Co, Cr, Cu, K, Mg, Mn, Mo, Ni, P, Se, and Zn) and ...
Bromine, Chlorine, and Iodine determination in soybean and its products by ICP-MS After Digestion Using Microwave-Induced Combustion

Barbosa, José Tiago Pereira; Santos, Clarissa Marques Moreira; Bispo, Lilia dos Santos; Lyra, Fernanda Henrique; David, Jorge Mauricio; Korn, Maria das Graças Andrade; Flores, Erico Marlon Moraes (2013)

A method for bromine, chlorine, and iodine determination in soybean and related products was developed by inductively coupled plasma mass spectrometry (ICP-MS) after digestion by microwave-induced combustion (MIC). Samples ...
Exposure to carbonyl compounds in charcoal production plants in Bahia, Brazil

Carvalho, Albertinho Barreto de; Kato, Mina; Rezende, Mariângela M.; Pereira, Pedro Afonso de Paula; Andrade, Jailson Bittencourt de (2013)

Studies have investigated the exposure levels of carbonyl compounds (CC) in the indoor and outdoor air of homes, vehicles, workplaces, urban and industrial areas, and rural sites. However, an investigation of these emissions ...
Determination of the mineral composition of Brazilian rice and evaluation using chemometric techniques

Silva, Douglas Gonçalves da; Scarminio, Ieda Spacino; Anunciação, Daniela Santos; Souza, Anderson Santos; Silva, Erik Galvão Paranhos da; Ferreira, Sergio Luis Costa (Brasil, 2013)

The mineral composition of Brazilian rice samples was determined and the data obtained were evaluated using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Nineteen commercial rice samples were ...
Myrciaine, a new nicotinic ester from Myrcia blanchetiana (Myrtaceae)

Cerqueira, Martins D. de; Souza Neta, Lourdes Cardoso de; Guedes, Maria L. S.; Rivelino, Roberto; Cruz, Frederico Guare (2013)

A nicotinic ester with a new carbon skeleton named myrciaine was obtained from hexane extract of stems of Myrcia blanchetiana using chromatographic methods and from leaves by supercritical CO2. The molecular structure was ...
Determination of sulfur in coal using direct solid sampling and high-resolution continuum source molecular absorption spectrometry of the CS molecule in a graphite furnace

Mior, Renata; Morés, Silvane; Welz, Bernhard; Carasek, Eduardo; Andrade, Jailson Bittencourt de (2013)

An analytical method has been developed for the determination of sulfur in coal using direct solid sample analysis in a graphite tube furnace and high-resolution continuum source molecular absorption spectrometry (HR-CS ...
Determination of mercury in phosphate fertilizers by cold vapor atomic absorption spectrometry

Jesus, Robson M. de; Silva, Laiana O. B.; Castro, Jacira T.; Azevedo Neto, André Dias de; Jesus, Raildo M. de; Ferreira, Sergio Luis Costa (2013)

n this paper, a method for the determination of mercury in phosphate fertilizers using slurry sampling and cold vapor atomic absorption spectrometry (CV QT AAS) is proposed. Because mercury (II) ions form strong complexes ...
Determination of N,N-dimethyltryptamine in beverages consumed in religious practices by headspace solid-phase microextraction followed by gas chromatography ion trap mass spectrometry

Gaujac, Alain; Dempster, Nicola M.; Navickiene, Sandro; Brandt, Simon D.; Andrade, Jailson Bittencourt de (2013)

A novel analytical approach combining solid-phase microextraction (SPME)/gas chromatography ion trap mass spectrometry (GC-IT-MS) was developed for the detection and quantification N,N-dimethyltryptamine (DMT), a powerful ...
Production of 5-hydroxy-7-methoxy-4-methylphthalide in a culture of Penicillium crustosum

Valente, Angela Maria Montes Peral; Ferreira, Antonio G.; Daolio, Cristina; Rodrigues Filho, Edson; Boffo, Elisangela Fabiana; Souza, Antonia Q. L.; Sebastianes, Fernanda Luiza de Souza; Melo, Itamar Soares de (2013)

The chemical reactions carried out by microorganisms have been used as a tool in modern chemistry. This paper reports the production of mycophenolic acid and a new phthalide by the endophytic fungus Penicillium crustosum ...
Determination and Evaluation Employing Multivariate Analysis of the Mineral Composition of Broccoli (Brassica oleracea L. var. Italica)

Santos, Ana Maria Pinto dos; Lima, Jeane dos Santos; Anunciação, Daniela Santos; Souza, Anderson Santos; Santos, Daniele Cristina Muniz Batista dos; Matos, Geraldo D. (2013)

Broccoli (Brassica oleracea L. var. Italica) is a vegetable food that belongs to the family Cruciferaceae, and it is a good source of vitamins and minerals. Among other characteristics, the kind of culture (conventional ...
A new tropane alkaloid and other constituents of Erythroxylum rimosum (Erythroxylaceae)

Ribeiro, Erika M. de O.; Lima, Luciano S.; David, Jorge Mauricio; Vale, Ademir Evangelista do; Lopes, Lucia M. Xavier; David, Juceni Pereira de Lima (2013)

A new tropane alkaloid, named the 7β-acetoxy-3β,6β-dibenzoyloxytropane (1), was isolated from a methanol extract of Erythroxylum rimosum O.E. Schulz leaves. Other known compounds were detected, including quercetin, ...
Sequential determination of Cd and Cr in biomass samples and their ashes using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis

Duarte, Alvaro T.; Dessuy, Morgana B.; Vale, Maria Goreti R.; Welz, Bernhard; Andrade, Jailson Bittencourt de (2013)

High-resolution continuum source graphite furnace atomic absorption spectrometry, because of the use of only one radiation source for all elements, offers the possibility of sequential determination of two or more elements ...
Evaluation of Sample Preparation Procedures for Trace Element Determination in Brazilian Propolis by Inductively Coupled Plasma Optical Emission Spectrometry and Their Discrimination According to Geographic Region

Korn, Maria das Graças Andrade; Guida, Mauro Agildo Barbosa; Barbosa, José Tiago Pereira; Torres, Ednildo Andrade; Fernandes, Andréa Pires; Santos, Josué Carinhanha Caldas; Dantas, Kelly das Graças Fernandes; Nóbrega, Joaquim de Araújo (2013)

Propolis is a complex mixture of substances collected by honeybees from buds or exudates of plants, beeswax, and other constituents, as pollen and sugars. The main purpose of this study was to evaluate two digestion ...
Cis–trans isomerization in the syntheses of ruthenium cyclam complexes with nitric oxide

Vidal, Robson da Silva; Doro, Fabio Gorzoni; Ferreira, Kleber Queiroz; Rocha, Zênis Novais da; Castellano, Eduardo Ernesto; Nikolaou, Sofia; Tfouni, Elia (2012)

The cis to trans isomerizations during the syntheses of trans-[Ru(NO)(OH)(cyclam)](PF6)2, from cis-[RuCl2(cyclam)]Cl, and [Ru(NO)Cl(cyclam)] (PF6)2, from cis-[RuCl2(dmso)4], are reported. The novel trans-[Ru(NO)(OH)(cyclam)](PF6)2 ...
Search for signatures of magnetically-induced alignment in the arrival directions measured by the Pierre Auger Observatory

Abreu, P.; Aglietta, M.; Ahn, E. J.; Albuquerque, Ivone Freire da Mota e; Allard, D.; Allekotte, I.; Allen, J.; Allison, P.; Pepe, Iuri Muniz (2012)

We present the results of an analysis of data recorded at the Pierre Auger Observatory in which we search for groups of directionally-aligned events (or ‘multiplets’) which exhibit a correlation between arrival direction ...

Mostrando ítems 1-20 de 835

Página siguiente

Buscar en DSpace

Búsqueda avanzada

Listar

Todo DSpace
Esta colección

Envíos recientes

Artigo Publicado em Periódico (Química): Envíos recientes

Buscar en DSpace

Listar

Todo DSpace

Esta colección

Mi cuenta