Chemometric Methods
Mostrando 1-12 de 67 artigos, teses e dissertações.
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1. Integrated UPLC-HRMS, Chemometric Tools, and Metabolomic Analysis of Forage Palm (Opuntia spp. and Nopalea spp.) to Define Biomarkers Associated with Non-Susceptibility to Carmine Cochineal (Dactylopius opuntiae)
Metabolomics, together with analytical methods and chemometric tools, point to new paths for selecting species that are resistant to pests and diseases. In this work, the forage palm species' metabolomic profile was investigated, and the relation between the chemical composition and resistance to Dactylopius opuntiae (carmine cochineal). The study was perfor
J. Braz. Chem. Soc.. Publicado em: 2021-08
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2. FASE SENSORA DE POLI(CLORETO DE VINILA) NA DETECÇÃO DE 17β-ESTRADIOL EM MEIO AQUOSO UTILIZANDO ESPECTROSCOPIA NO INFRAVERMELHO MÉDIO E QUIMIOMETRIA
In recent years, estrogens have gained notable attention among emerging pollutants, increasingly leading to the need for less laborious analytical methods. Optical sensors are a promising technology for the determination of chemical contaminants in water, acting as an alternative screening method. The aim of this work was to evaluate the performance of poly(
Quím. Nova. Publicado em: 2020-09
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3. A multivariate approach to differentiate yerba mate (Ilex paraguariensis) commercialized in the southern Brazil on the basis of phenolics, methylxanthines and in vitro antioxidant activity
Abstract The consumption of yerba mate beverages is related to several health benefits. These desirable properties are mainly due to the bioactive compounds. However, the levels of those compounds are directly affected by factors such as geographical origin. This study aimed to use chemometrics to evaluate the antioxidant compounds of yerba mate (consumed as
Food Sci. Technol. Publicado em: 2020-09
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4. 1H NMR and Chemometric Methods to Estimate the Octane Number in Brazilian C Gasolines
Brazilian gasoline type C can be purchased with octane number as the main difference. This quality parameter directly affects the price. Intermediate formulations may not be easily distinguished from conform samples due to similarity in visual appearance and physicochemical properties. The use of anhydrous ethanol as an additive also influences the octane va
J. Braz. Chem. Soc.. Publicado em: 2020-08
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5. ANÁLISE DE AMOSTRAS DE COMBUSTÍVEIS POR FOTOMETRIA, NIR PORTÁTIL E RMN DE 1H - UMA COMPARAÇÃO COM OS RESULTADOS ENCONTRADOS POR TÉCNICAS NORMATIZADAS
It has been recurring adulterations in fuels (such as gasoline, ethanol and diesel), being necessary the exploration of the use of more modern analytical techniques capable of controlling the quality of these fuels, since some regulated tests may be inefficient to detect the adulteration. Among them, it is highlighted proton nuclear magnetic resonance (1H NM
Quím. Nova. Publicado em: 2020-02
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6. CHEMOMETRIC TOOLS AND FTIR-ATR SPECTROSCOPY APPLIED IN MILK ADULTERATED WITH CHEESE WHEY
Brazilian law forbids the addition of cheese whey in milk. However, adulteration with cheese whey is one of the most applied fraud due to its low cost. The detection of this fraud is the quantification of Caseinomacropeptide (CMP). The CMP is a constituent of the whey that can be used as adulteration marker. Thus, an analytical method capable of identifying
Quím. Nova. Publicado em: 02/05/2019
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7. Chemo-characterization and optimization of macro and micro nutrients for exopolysaccharides and mycelia growth in pleurotus tuberregium (RUMPH, EX FR)
Abstract Exoploysaccharides are potential nutraceutic, probiotic, phamarceutic and cosmesceutic natural products in fungi. Pleurotus tuberregium is an underutilized tropical fungus that is useful as food with recent reports of pharmacological activities. The present study evaluated and characterized environmental conditions and nutrients for optimal P. tube
Food Sci. Technol. Publicado em: 11/04/2019
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8. Characterization of leaves used in infusion preparation grown in northeastern Brazil by chemometric methods based on their multi-elemental composition
Abstract In many places of the world, medicinal plants represent the only form of treatment for various diseases. This work aimed to determine and correlate minerals of infusions and leaves of medicinal plants grown in Northeastern Brazil. Principal component and hierarchical cluster analysis and Pearson correlation were performed. The higher content of Na
Food Sci. Technol. Publicado em: 28/05/2018
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9. Volatile Compounds from the Bark Bugs Phloea subquadrata and Phloeophana longirostris (Heteroptera: Phloeidae)
Phloea subquadrata and Phloeophana longirostris are subsocial species that differ from each other in their host plants and degrees of aggregation. Until recently, only ten low-molecular weight compounds, a sesquiterpene, and dimers of (E)-4-oxo-2-hexenal had been reported from the contents of P. subquadrata glands. Here, the main goal was to distinguish the
J. Braz. Chem. Soc.. Publicado em: 2017-10
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10. Detection of Counterfeit Durateston® Using Fourier Transform Infrared Spectroscopy and Partial Least Squares - Discriminant Analysis
Medicines containing anabolic steroids are one of the main targets for counterfeiting worldwide, including Brazil. The aim of this work was to propose a method for discriminating original and counterfeit Durateston® ampoules by Fourier transform infrared spectroscopy (FTIR) followed by chemometric analysis. Ninety-six ampoules of Durateston®, 49 originals
J. Braz. Chem. Soc.. Publicado em: 2017-07
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11. DETERMINAÇÃO ESPECTROFOTOMÉTRICA DE WPNI E HMF EM LEITE UHT ATRAVÉS DA ANÁLISE POR COMPONENTES PRINCIPAIS
During heat treatment milk suffers changes among which whey proteins insolubility and Maillard reaction can be monitored using spectrophotometric methods by determining the whey protein nitrogen (WPNI) and 5-hydroxymethylfurfural (HMF). The aim of this work was the evaluation of heat treatment in commercial UHT milk samples through HMF and WPNI determination
Quím. Nova. Publicado em: 2016-07
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12. PROPOSTA EXPERIMENTAL DIDÁTICA PARA O ENSINO DE ANÁLISE DE COMPONENTES PRINCIPAIS
Principal component analysis (PCA) is a chemometric method that allows for the extraction of chemical information that would otherwise be impossible to determine. Teaching chemometrics to undergraduates can contribute to the overall professional development and training of new teachers, whose profiles have been gaining attention due to the current demand for
Quím. Nova. Publicado em: 2016-02