Analytical Solution
Mostrando 1-12 de 525 artigos, teses e dissertações.
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1. Thermal Infrared Enthalpimetry Method for the Determination of Hypochlorite in Bleaching Solutions
Thermal infrared enthalpimetry (TIE) was used for hypochlorite determination in commercial hypochlorite-based bleaching solutions. Experimental parameters were evaluated for the reaction with a hydrogen peroxide solution. The most relevant conditions were 5% H2O2 (m/m) solution, stirring speed of 250 rpm, dispensing rate of 0.57 mL s-1, and 10 s after reacti
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. NMR Relaxometry Applied to Chemical Studies of Paramagnetic Metal Cation Complexes: Fundamentals and Applications
Low field time-domain nuclear magnetic resonance (TD-NMR) relaxometry of paramagnetic metal cations (PMC) has been widely used to study and improve contrast agents for magnetic resonance imaging (MRI). However, despite its remarkable potential, TD-NMR is rarely used to study PMC complexes, and coordination compounds in non-biomedical application. Therefore,
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Additive Manufacturing towards the Fabrication of Greener Electrochemical Sensors for Antioxidants
Additive manufacturing is an emerging tool that has contributed to the sustainable fabrication of devices in several areas based on the concept of “zero waste”. Considering extrusion-based manufacturing (or 3D printing), polylactic acid (PLA) has been highlighted due to its biodegradability, obtention from renewable sources, and compatibility for 3D prin
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. INTERDISCIPLINARY EDUCATION THROUGH THE DEVELOPMENT OF A COST-EFFECTIVE PHOTOMETRIC PH METER SENSOR USING NATURAL PIGMENTS
There is a trend of development of analytical methodologies and technologies that allow in situ analysis, producing accurate information in real time, at low cost, using homemade experiments and devices to increase interest in scientific knowledge with a constructive approach in an interdisciplinary perspective in Chemistry Education. In this context, a phot
Química Nova. Publicado em: 2022
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5. Meshless Methods for Computation of Overhead Transmission Lines Electromagnetic Fields
Abstract The meshless element-free Galerkin method (EFGM) is used to solve partial differential equations responsible for obtaining the electromagnetic fields generated by a transmission line. For this purpose, a 2D model based in a real transmission line is constructed and simulated. The results obtained by EFGM have good accuracy and they are compared agai
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-06
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6. Alternative Approaches Applied to Inductively Coupled Plasma Techniques: Multi-Flow and Two-Flow Calibration
Multi-flow calibration (MFC) is based on monitoring the analytical signal from a single calibration standard solution at several different nebulization gas flow rates (Q), which normalizes plasma conditions and minimizes matrix effects. In the present study, MFC was evaluated, for the first time, applied to inductively coupled plasma optical emission spectro
J. Braz. Chem. Soc.. Publicado em: 2021-04
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7. Development of a Methodology Based on Extraction Induced by Emulsion Breaking for Copper Determination in Gasohol by Graphite Furnace Atomic Absorption Spectrometry
The development of a method based on extraction induced by emulsion breaking (EIEB) aiming copper determination in gasohol using graphite furnace atomic absorption spectrometry (GF AAS) is reported. Emulsification of the gasohol samples was carried out using nitric acid solution, (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol surfactant (Triton X-114),
J. Braz. Chem. Soc.. Publicado em: 2021-02
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8. QUANTIFICACAO DE NANOPARTICULAS DE PRATA EM UM PRODUTO FARMACEUTICO POR ESPECTROFOTOMETRIA E POTENCIOMETRIA: UMA PROPOSTA PARA AULAS PRATICAS DE QUIMICA ANALITICA
Spectrophotometry and potentiometry techniques were used to quantify silver in an ophthalmic solution. A standard solution of silver nanoparticles was synthesized, from which an analytical method was developed to quantify silver in the sample. Potentiometric titrations of three samples were made, using an electrochemical cell containing an alternative metall
Quím. Nova. Publicado em: 2021-01
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9. USO DE UM SCANNER DE MESA E ESPUMA DE POLIURETANO PARA QUANTIFICAÇÃO DE FERRO TOTAL EM CÁPSULAS DE SUPLEMENTOS ALIMENTARES
In this work, an alternative and low-cost technique for the extraction and quantification of Fe (total) from food supplements by digital image analysis is shown. The method is based on the complexation of Fe ions in solution with the 8-hydroxyquinoline ligand, forming a colored complex that is extractable from aqueous solution to polyurethane foam, coloring
Quím. Nova. Publicado em: 2021-01
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10. Determining Mercury in Sediment Samples by Extraction Using a Novel-Chelating Reagent Dithiothreitol (DTT) Followed by Cold Vapor Atomic Fluorescence Spectrometry (CV-AFS)
A new analytical protocol has been developed for the determination of mercury in surface sediments using dithiothreitol (DTT) as a new chelating reagent for the extraction. This protocol requires a small sample mass (250 mg), 4.0 mL of a 0.1 M (pH = 9.0) aqueous DTT solution, and sonication for 30 min, followed by cold vapor atomic fluorescence spectrometry
J. Braz. Chem. Soc.. Publicado em: 2020-12
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11. INFLUÊNCIA DA FORÇA IÔNICA NA ESTIMATIVA DE pKa POR MÉTODO VOLTAMÉTRICO
The voltammetry is an important analytical technique and also useful for pKa determination. It is a usual procedure of this technique to employ inert electrolyte concentration 100 times higher than redox compound concentration further a pH buffer. However, the ionic strength changes with the solution pH. In this work, we study the consequences of this proced
Quím. Nova. Publicado em: 2020-12
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12. Error Analysis of the Numerical Method for Correcting the Propagation of EM waves in the Troposphere
Abstract Electromagnetic (EM) waves do not travel in straight lines in the troposphere due to refraction. This leads to errors in many engineering applications. In order to correct these errors, a numerical solution based on the difference method has been proposed, which can reveal the degree of EM wave bending owing to atmospheric refraction, moreover, it c
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-09