Flame Atomic Absorption Spectrometry
Mostrando 1-12 de 151 artigos, teses e dissertações.
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1. Atomic Absorption Spectrometry as an Alternative to Determine the Presence of Gold Nanoparticles on or in Silica Matrix
Two different gold-silica-based nanomaterials were prepared: (i) silica-supported gold nanoparticles (AuNP/SiO2); and (ii) gold-silica core-shell nanoparticles (AuNP@SiO2). Three strategies for sample treatment (S), consisting in acid treatments, were employed: (S1) HNO3; (S2) HNO3 + HCl; and (S3) HF + HNO3 + HCl, applying microwave oven digestion for S2 and
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. SEQUENTIAL MULTI-ELEMENT DETERMINATION OF TRACE-METALS IN BIODIESEL SAMPLES USING HR-CS FAAS
In this work the feasibility of sequential multi-element determination of Zn, Fe, Mg, Cu, Na, K, Cr, Al and Ca in biodiesel samples by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was investigated. Biodiesel samples obtained from different sources and different chemical processes were analysed. The samples were diluted w
Quím. Nova. Publicado em: 2021-02
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3. MAIN MINERALS AND ORGANIC COMPOUNDS IN COMMERCIAL ROASTED AND GROUND COFFEE: AN EXPLORATORY DATA ANALYSIS
Coffee is one of the most popular beverages in the world, however, little information is found regarding the mineral composition of commercial roasted and ground coffees (RG) and its correlation with organic bioactive compounds. 21 commercial Brazilian RG coffee brands - 9 traditional (T) and 12 extra strong (ES) roasted ones - were analyzed for the Cu, Ca,
Quím. Nova. Publicado em: 2021-01
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4. Selected minerals concentration and microbiological safety in non-carcass bovine components of “PANELADA” dish
Abstract “Panelada” is a typical dish from Brazil, made up of some bovine non-carcass components (intestine, rumen and ox feet), whose nutritional value and microbiological quality are not reported. The total contents of selected minerals were determined using flame atomic absorption spectrometry (FAAS) and electrothermal (ETAAS) for samples of raw, seas
Food Sci. Technol. Publicado em: 2020-12
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5. AVALIAÇÃO DE NANOTUBOS DE CARBONO FUNCIONALIZADOS VISANDO O DESENVOLVIMENTO DE MÉTODOS DE PRÉ-CONCENTRAÇÃO DE ÍONS METÁLICOS E DETERMINAÇÃO POR TÉCNICAS ESPECTROMÉTRICAS E ELETROANALÍTICAS
This review focuses on the use of functionalized carbon nanotubes (CNTs) on the development of preconcentration methods with substantial contributions on selectivity and sensitivity for metal ions determination. CNTs have been usually employed in the development of preconcentration/speciation coupled to spectroanalytical techniques for ions determination at
Quím. Nova. Publicado em: 2020-09
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6. Voltammetric Determination of Free and Total Manganese in Tea Infusions
Tea infusions are a source of mineral nutrients, including manganese. Although it is classified as an essential element, the excess of manganese is toxic for humans and its toxicity depends on its bioavailability. In this context, we propose a simple procedure to determine free and total manganese in black tea infusions by square-wave voltammetry (SWV). Free
J. Braz. Chem. Soc.. Publicado em: 2020-07
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7. Concentration of Metals in Plant Litter Produced in Regions of Caatinga in Southwest Bahia, Brazil
Plant litter has several functions in a forest ecosystem. Studies about plant litter are of great importance to better understand and conserve ecological environments. The objective of this study was to investigate the concentration of metals (Fe, Co, Ca, Cu, Ni, Mg, Mn and Zn) in Caatinga plant litter in the southwest region of Bahia. Plant litter was colle
J. Braz. Chem. Soc.. Publicado em: 2020-07
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8. Biosorption Potential of the Aspergillus sp. and Insights into Secondary Metabolism in the Presence of Copper and Lead
The fungus Aspergillus sp. was isolated from copper mining rejects and cultured in a liquid culture medium (potato dextrose, PD) enriched with CuSO4.5H2O and Pb(NO3)2 in different concentrations. By flame atomic absorption spectrometry (FAAS) it was observed that fungus absorbed 86% of both copper and lead, with initial concentrations of 100, 500 and 1000 mg
J. Braz. Chem. Soc.. Publicado em: 2020-03
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9. Use of Arduino in the Development of a New and Fast Automated Online Preconcentration System Based on Double-Knotted Reactor for the Mn Determination in Tea Samples by Flame Atomic Absorption Spectrometry (F AAS)
In the present paper, an automated online preconcentration system based on the use of two knotted reactors (KR) was developed for Mn determination in tea samples by flame atomic absorption spectrometry (F AAS). The system automation was performed by using four solenoid valves to switch sample streams and reagents. Valves were driven electronically by an inte
J. Braz. Chem. Soc.. Publicado em: 2020-01
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10. Multi-Element Evaluation in Black Pepper (Piper nigrum L.) According to the Processing
Black pepper is one of the most consumed spices worldwide and the evaluation of trace elements content is essential to promote consumer safety. In this study, concentrations of the elements As, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Se, V and Zn was determined in samples of black peppercorn (n = 25) and ground black pepper (n = 25) to verify how processing affects
J. Braz. Chem. Soc.. Publicado em: 2020-01
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11. Magnetic Solid-Phase Microextraction for Lead Detection in Aqueous Samples Using Magnetite Nanoparticles
A magnetic solid-phase microextraction procedure was developed to detect lead in aqueous samples by flame atomic absorption spectrometry (FAAS). Fe3O4 nanoparticles were synthesized by coprecipitation and the crystalline phase was confirmed by X-ray diffraction. The point of zero charge (PZC) indicated that the oxide surface was negatively charged at pH leve
J. Braz. Chem. Soc.. Publicado em: 2020-01
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12. Performance of Avocado Seed Activated Carbon as Adsorbent for Highly Sensitive Determination of Cd Using a Flow Injection System Online Coupled to TS-FF-AAS
A flow-injection preconcentration system using detection by the thermospray flame furnace atomic absorption spectrometry (FIA-TS-FF-AAS) is proposed. Cd2+ are adsorbed on avocado seed activated carbon (ASAC) packed into a cylindrical mini-column and eluted using HCl solutions for the detection system. A 25–1 fractional factorial and Doehlert matrix design
J. Braz. Chem. Soc.. Publicado em: 2020-01