Chemometrics Analyses
Mostrando 1-12 de 15 artigos, teses e dissertações.
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1. 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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2. Headspace analysis and characterisation of South African propolis volatile compounds using GCxGC–ToF–MS
ABSTRACT Propolis also known as "bee glue or bee resin" is a resinous mixture of bee saliva or bee wax and exudate from tree trunks and flowers, produced by honeybees. The composition of propolis varies depending on the vegetation the bees can access. It is therefore expected that propolis obtained from various localities may have different chemical profiles
Rev. bras. farmacogn.. Publicado em: 26/08/2019
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3. HR-MAS NMR Allied to Chemometric on Hancornia speciosa Varieties Differentiation
This work describes the potential of chemometric analyses applied to 1H high-resolution magic angle spinning nuclear magnetic resonance (1H HR-MAS NMR) data for the chemotaxonomic investigation of Hancornia speciosa (Apocynaceae) varieties. This plant, popularly known as mangaba, has a complex morphological differentiation and thus chemical analyses can be u
J. Braz. Chem. Soc.. Publicado em: 2018-04
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4. APPLICATION OF PARAFAC AND OPLS-DA ANALYSES ON HPLC FINGERPRINTS FOR THE CHARACTERIZATION OF Hibiscus sabdariffaCALYXES
The calyxes of Hibiscus sabdariffa are used in traditional medicine around the world. However, quality assurance protocols and chemical variability have not been previously analyzed. In the present study, chemical characterization of a set of samples of H. sabdariffa calyxes commercialized in Colombia was accomplished with the aim to explore the chemical var
Quím. Nova. Publicado em: 2016-02
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5. Biomimetic Sensor for Detection of Hydrochlorothiazide Employing Amperometric Detection and Chemometrics for Application in Doping in Sports
This work describes a simple and cost-effective method for quantitative determination of hydrochlorothiazide using biomimetic sensor based on a carbon paste modified with hemin (biomimetic catalyst of the P450 enzyme). The sensor was evaluated using cyclic voltammetry and amperometry for its electrochemical characterization and quantification, respectively.
J. Braz. Chem. Soc.. Publicado em: 2015-10
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6. Grape juice quality control by means of ¹H nmr spectroscopy and chemometric analyses
This work shows the application of ¹H NMR spectroscopy and chemometrics for quality control of grape juice. A wide range of quality assurance parameters were assessed by single ¹H NMR experiments acquired directly from juice. The investigation revealed that conditions and time of storage should be revised and indicated on all labels. The sterilization proc
Quím. Nova. Publicado em: 2014
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7. Application of fourier transform infrared spectroscopy, chemical and chemometrics analyses to the characterization of agro-industrial waste
Agroindustrial waste in general presents significant levels of nutrients and organic matter and has therefore been frequently put to agricultural use. In this context, the objective of this study was to determine the chemical composition, nitrogen, phosphorus, potassium, calcium, magnesium and carbon content, as well as the qualitative characteristics throug
Quím. Nova. Publicado em: 2014
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8. Chemical composition of volatiles from male and female specimens of Baccharis trimera collected in two distant regions of southern brazil: a comparative study using chemometrics
GC/MS/FID analyses of volatile compounds from cladodes and inflorescences from male and female specimens of Baccharis trimera (Less.) DC. collected in the states of Paraná and Santa Catarina, Brazil, showed that carquejyl acetate was the primary volatile component (38% to 73%), while carquejol and ledol were identified in lower concentrations. Data were sub
Quím. Nova. Publicado em: 2013
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9. Avaliação da influência da matéria orgânica, na determinação quantitativa de metais em amostras de sedimento, por espectrometria de absorção atômica e análise de metais traços por fluorescência de raios-X
The proposal of this work is to evaluate the influence of the organic matter on the results of the analyses of the metals (Zn, Pb, Al, Cu, Cr, Fe, Cd e Ni) for Atomic Absorption Spectrometry (AAS), so much in the extraction stage as in the reading using for that the chemometrics. They were used for this study sample of bottom sediment collected in river Jund
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/02/2011
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10. Multi-core computation in chemometrics: case studies of voltammetric and NIR spectrometric analyses
A aplicação de técnicas quimiométricas sofisticadas a grandes conjuntos de dados tem se tornado possível devido aos contínuos aprimoramentos tecnológicos em computadores comerciais. Recentemente, tais aprimoramentos têm sido obtidos principalmente através da introdução de processadores com múltiplos núcleos. Contudo, o uso eficiente de hardware
Journal of the Brazilian Chemical Society. Publicado em: 2010
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11. ESTUDO FITOQUÍMICO E ATIVIDADES BIOLÓGICAS DE JATROPHA CURCAS L. / PHYTOCHEMICAL STUDY AND BIOLOGICAL ACTIVITIES OF JATROPHA CURCAS L.
No presente trabalho foi determinado, pela primeira vez, os compostos voláteis das folhas frescas e secas de Jatropha curcas L. pela técnica de hidrodestilação, para seis diferentes acessos (denominados de PM-2, PM-7, PM-10, PM-11, PM- 12 e PM-14) e uma cultivar (EPAMIG, denominada de EMB). As análises foram realizadas através de CG/EM, obtendo-se o (Z
Publicado em: 2010
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12. Avaliação do emprego de técnicas de RMN e IV aliadas a métodos quimiométricos na investigação de autenticidade da droga vegetal comercial quebra-pedra / Evaluation of employment of nmr techniques and ir combined with chemometric methods in the inquiry of authenticity of the "quebra-pedra" commercial herbal drug
The importance of medicinal plants and their use in industrial purposes is increasing. Among the herbal drugs being commercialized there are "quebra-pedras". According to the the Brazilian Pharmacopoeia, the recognized officially species as medicinal plants having the attributed pharmacological properties to "quebra-pedras" are: Phyllanthus niruri and Phylla
Publicado em: 2009