Chemometrics
Mostrando 1-12 de 138 artigos, teses e dissertações.
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1. Encoding of Luminescent Ink Markers Using Low-Level Data Fusion and Chemometrics
The identification and analysis of documentary fraud is always a challenge for forensic science. Document analysis has proven to be an important branch of forensics in elucidating the authenticity of documents. The development and incorporation of luminescent inks in authentic documents have proved to be an excellent security feature. This paper purposes the
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Perfil cientométrico da Quimiometria no Brasil
The interest of researchers in understanding the stage of development of specific areas of knowledge is a way to understand their scientific maturity and their capacity for consolidation. This “popularization” of the knowledge of researchers working in a specific area of knowledge also allows a greater ability to recognize where science is produced and w
Química Nova. Publicado em: 2022
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3. Simultaneous Quantification of Amorphous and Crystalline Valsartan in Tablets Using Raman Spectroscopy and Chemometrics Tools
Valsartan is an antihypertensive active pharmaceutical ingredient (API), it is used in the amorphous state in the commercial products. As amorphous materials are metastable, amorphous valsartan can crystallize to valsartan E, promoting changes in the dissolution and bioavailability of the drug. Tablets containing metastable forms of APIs need special conditi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. How Much do the Environmental Conditions Interfere with the Essential Oils of Eugenia spp. L. (Myrtaceae)?
Eugenia is the largest neotropical genus in the Myrtaceae family. The genus has a wide geographical distribution, occurring from Mexico to Argentina. Eugenia species are rich in essential oils. Essential oils have applications in perfumery, cosmetics, food, pesticides and medicines. Several factors can influence the chemical composition and yield of essentia
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Spectroscopic techniques combined with chemometrics to study organic matter in tropical soils with different degrees of pedogenetic evolution
Understanding of the organomineral interactions in soil can elucidate the humic substances (HS) formation and the humification process. This study aimed to structurally characterize the humic acids (HA) formed in tropical soils with different pedogenesis degrees. The HA fraction was extracted from soil samples in the superficial horizons of an Inceptisol and
Química Nova. Publicado em: 2022
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6. X-ray Scattering and Chemometrics as Tools to Assist in the Identification of Gunshot Residues by Wavelength Dispersive X-ray Fluorescence Spectrometry
Wavelength dispersion X-ray fluorescence spectrometry (WDXRF) is a non-destructive technique and therefore attractive for gunshot residues (GSR) analysis. It is well known for determination of inorganic constituents of samples. However, X-ray scattering region spectral data is not commonly used, although it may provide information about organic constituents
J. Braz. Chem. Soc.. Publicado em: 2020-12
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7. Quick Identification of the Time of Maturation of Artisanal Minas Cheese by FTIR-ATR Spectroscopy and Multivariate Techniques
The objective of this work is the identification of cheese maturation time using attenuated total reflection Fourier transform spectroscopy (FTIR-ATR) data and analytical measurements associated with chemometrics techniques. Minas artisanal cheeses were collected from 8 producers matured at times 1, 7, 14, 21, 28, 45 and 60 days, fractioned in rind and crumb
J. Braz. Chem. Soc.. Publicado em: 2020-10
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8. 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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9. Determination of Ethanol in Gel Hand Sanitizers Using Mid and Near Infrared Spectroscopy
Alcohol-based gel hand sanitizers became very popular during the COVID-19 (coronavirus disease 2019) pandemic. In Brazil, several irregular factories emerged requiring an efficient control by the police and regulatory agencies to guarantee product quality. This problem required a method to determine ethanol content, which led to the development of two method
J. Braz. Chem. Soc.. Publicado em: 2020-09
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10. 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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11. 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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12. Fast Verification of Buffalo’s Milk Authenticity by Mid-Infrared Spectroscopy, Analytical Measurements and Multivariate Calibration
Mid-infrared spectroscopy (MID), chemical composition and physicochemical characteristics associated with chemometrics were used to rapidly detect and quantify the amount of cow’s milk added in buffalo’s milk. A total of 165 samples, divided into buffalo’s milk, buffalo’s milk added with cow’s milk (10 to 90%) and cow’s milk were evaluated to obt
J. Braz. Chem. Soc.. Publicado em: 2020-07