Sample Preparation
Mostrando 1-12 de 705 artigos, teses e dissertações.
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1. An Eco-Friendly Proposal by Integrating Chromatographic Fingerprinting and Multivariate Control Chart in a Non-Target Analysis to Evaluate Grape Juices from Different Farming Practices
A potential eco-friendly method without organic solvents is presented by integrating a chromatographic fingerprint and multivariate control chart based on Q residuals to differentiate grape juices from different farming practices. The sample preparation was only water dilution, and the mobile phase was water acidified with sulfuric acid, which can be readily
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Determination of Ethyl Carbamate in Commercial Sweetened Sugar Cane Spirit by ESI-MS/MS Using Modified QuEChERS and 18-Crown-6/Trifluoroacetic Acid Spiking Additives
A fast, sensitive, and selective direct injection electrospray tandem mass spectrometry (DI ESI MS/MS) method that is able to quantify ethyl carbamate in commercial sweetened sugar cane spirit is described. The preparation method uses a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) with potassium carbonate added to sweetened sugar cane
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Simple Spectrophotometric Determination of Iron in Diesel Oil after Sample Preparation Employing Extraction Induced by Emulsion Breaking
This work reports the development of a simple and fast method for the spectrophotometric determination of Fe in diesel oil using the classic reaction with 1,10-phenanthroline after its extraction induced by emulsion breaking (EIEB). The extraction parameters of EIEB were optimized (concentration of HNO3 and Triton X-100® in the emulsifying solution) as well
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Development of a ceramic membrane for emulsion water-diesel treatment
Abstract The purpose of this study was the development of a low-cost ceramic tubular membrane, using inexpensive materials, namely natural clay, and graphite as a porogenic agent. Such a low-cost membrane can be used as filters or porous supports for the preparation of multilayer ceramic membranes. Extrusion was used as a shape-forming method for this purpos
Cerâmica. Publicado em: 2022
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5. Simultaneous GC-NCI-MS Determination of Persistent Organic Pollutants and Current-Use Pesticides in Breast Milk Samples
To preserve human health, persistent organic pollutants (POPs) and current-use pesticides (CUPs) should be monitored in fatty tissues, including breast milk. Therefore, this study aimed to optimize sample preparation conditions using a 32 factorial design for the determination of POPs and CUPs by gas chromatography coupled to mass spectrometry with negative
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. Determinação de etil-glicuronídeo e etil-sulfato em sangue por UPLC-MS/MS: aplicação clínica em vítimas de trauma
We developed a UPLC-MS/MS method for the quantification of the ethanol metabolites ethyl-glucuronide (EtG) and ethyl-sulfate (EtS) in blood samples. Sample preparation was a protein precipitation with acetonitrile 0.1% formic acid containing internal standards (IS) 0.5 µg mL-1 EtG-D5 and EtS-D5. Chromatographic separation was performed in a fluoro-phenyl co
Química Nova. Publicado em: 2022
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7. Development of Analytical Method for Determination of Inorganic Constituents in Powder Refreshment Using Dilute Mineral Acids and Detection by ICP OES
An analytical method for multi-elementary determination in powder refreshment, based on sample digestion using dilute mineral acids and detection by inductively plasma coupled optical emission spectrometry (ICP OES) is proposed. Chemometric tools, such as fractional factorial design and principal component analysis (PCA) and hierarchical cluster analysis (HC
J. Braz. Chem. Soc.. Publicado em: 2021-07
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8. Solventes eutéticos naturais profundos (NADES) no preparo de amostras de rocha fosfática e suplemento mineral para determinação elementar por técnicas de plasma
Natural deep eutectic solvents (NADES) based on xylitol, citric acid, and malic acid were synthesized and used in ultrasound-assisted extraction (UAE) and heating-bath extraction of phosphate rock and mineral supplement samples. Arsenic, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS) and i
Quím. Nova. Publicado em: 2021-06
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9. Rheology of mine tailings deposits for dam break analyses
Abstract This article deals with the rheology of tailings deposits related to dam break analysis. The material used was a fine tailings from iron ore processing. Geotechnical and rheological characterization of these tailings were performed. The rheological characterization consisted of rotational and oscillatory tests. It was observed that the rheological p
REM, Int. Eng. J.. Publicado em: 2021-06
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10. Sample Preparation Using TMAH and Nitric Acid for Multielement Determination in Crustacean Samples by MIP OES
This study proposes a simple sample preparation procedure using tetramethylammonium hydroxide (TMAH) and nitric acid (HNO3) to determine Cr, Cu, Fe, K, Mg, Mn, and Zn concentrations in shrimp (Macrobrachium amazonicum) and crab (Ucides cordatus) samples from the Amazon region by microwave-induced plasma optical emission spectrometry (MIP OES). The sample sol
J. Braz. Chem. Soc.. Publicado em: 2021-03
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11. Identification of Synthetic Drugs on Seized Blotter Papers Using ATR-FTIR and PLS-DA: Routine Application in a Forensic Laboratory
Blotter papers seizures containing synthetic drugs have intensified over the last decades. These drugs were originally conceived as “legal” alternatives to traditional illicit drugs, designed to mimic their effects and circumvent control agencies. Reference methods for determining these substances on blotter papers are based on chromatographic techniques
J. Braz. Chem. Soc.. Publicado em: 2021-03
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12. 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