Linearity
Mostrando 13-24 de 736 artigos, teses e dissertações.
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13. DETERMINATION OF THE PESTICIDES IN WATER USED IN THE CULTURE AND PROCESSING OF POTATOES
The contamination of water bodies by pesticide residues through direct flow, leaching and other methods has motivated the development of analytical methods for the determination of these compounds in water. A vortex-assisted liquid-liquid microextraction method followed by gas chromatography coupled to mass spectrometry for the determination of anilazine, li
Quím. Nova. Publicado em: 2020-09
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14. HPLC METHOD IMPROVEMENT FOR 4-NONYLPHENOL DETERMINATION IN ANAEROBIC REACTORS: DECREASING SOLVENT CONSUMPTION AND WASTE GENERATION
The aim of this study was to develop a chromatographic method for 4-NP determination in anaerobic batch reactors using low amount of organic solvents and also evaluate 4-NP degradation in the presence of different co-substrates. Chromatographic parameters was improved for stationary phase (C-8 column), mobile phase (acetonitrile/water solution 90:10, v:v), c
Quím. Nova. Publicado em: 2020-09
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15. LIMONENE QUANTIFICATION BY GAS CHROMATOGRAPHY WITH MASS SPECTROMETRY (GC-MS) AND ITS EFFECTS ON HYDROGEN AND VOLATILE FATTY ACIDS PRODUCTION IN ANAEROBIC REACTORS
The inhibition effect of limonene on the organisms involved in anaerobic reactors may affect obtaining H2 in this process. Rapid and precise limonene quantification is desirable to characterize wastewaters. The objective of this research was to develop a Gas Chromatography Coupled to Mass Spectrometry (GC-MS) method to determine limonene concentration in liq
Quím. Nova. Publicado em: 20/07/2020
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16. Simultaneous Quantification of Plasma Catecholamines and Metanephrines by LC-MS/MS
The quantification of the low levels of catecholamines and metanephrines in biological fluids is important for clinical screening of pheochromocytoma/paraganglioma and diagnosis of overtraining syndrome in athletes. We introduce a novel, accurate and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of
J. Braz. Chem. Soc.. Publicado em: 2020-07
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17. A Choline Chloride-Ethylene Glycol Deep Eutectic Solvent Based on Magnetic Polydopamine with Preconcentration and Determination for Sulfonylurea Herbicides in Water Samples
In this study, a novel deep eutectic solvent (DES) containing choline chloride and ethylene glycol was synthesized, and the magnetic polydopamine (PDA) was modified with this deep eutectic solvent to form Fe3O4@PDA-DES. Fourier transformed infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer were used to characterize the pro
J. Braz. Chem. Soc.. Publicado em: 2020-07
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18. The Role of 18F-FDG PET/CT in Cardiac Sarcoidosis
The inhibition effect of limonene on the organisms involved in anaerobic reactors may affect obtaining H2 in this process. Rapid and precise limonene quantification is desirable to characterize wastewaters. The objective of this research was to develop a Gas Chromatography Coupled to Mass Spectrometry (GC-MS) method to determine limonene concentration in liq
Int. J. Cardiovasc. Sci.. Publicado em: 2020-07
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19. The Catalytic Action of Copper Ions and the Rosemary Extract Antioxidant Effect in the Biodiesel Oxidation Reaction and the Implication in Arrhenius Behavior
Biodiesel contains esters in its composition which make it susceptible to oxidation. Among the factors that cause this reaction is the contamination with metal ions. In the present work, it was analyzed biodiesel samples obtained from a mixture containing 39.0% m/m soybean oil, 22.0% m/m beef tallow and 39.0% m/m poultry fat using a methyl route. Copper ions
J. Braz. Chem. Soc.. Publicado em: 2020-06
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20. Rapid Determination of Vitamins D2 and D3 in Dairy Products by High-Performance Liquid Chromatography after Solid Phase Extraction Based on Polystyrene/Polypyrrole Composite Nanofibers
The detection of vitamin D in complex samples is challenging because of the instability of vitamin D in sample preparation. To resolve this problem, packed-fiber solid-phase extraction (PFSPE) has been successfully developed for the pre-treatment of samples containing vitamin D2 (D2) and vitamin D3 (D3) in dairy products. Based on PFSPE, vitamin D could avoi
J. Braz. Chem. Soc.. Publicado em: 2020-06
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21. Quantification of Arsenic, Cadmium, Mercury and Lead in Pineapple: Method Development, Validation and Evaluation of In-House Reference Materials
A method for quantification of arsenic, cadmium, mercury, and lead in pineapple using inductively coupled plasma-mass spectrometry (ICP-MS) was developed, validated, and used to test the homogeneity and stability of in-house reference materials. The method was tested at the regulation levels given by the Food and Agriculture Organization of the United Nation
J. Braz. Chem. Soc.. Publicado em: 2020-06
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22. Determination of Methanol in Gasoline and Ethanol Fuels by High-Performance Liquid Chromatography
Gasoline and ethanol fuels have been adulterated with methanol in Brazil. Methanol is not permitted in concentrations greater than 0.5 vol% due its toxicity but its lower price stimulates the adulteration. A new approach for quantitative analysis of methanol in gasoline and ethanol fuels is reported employing high-performance liquid chromatography coupled wi
J. Braz. Chem. Soc.. Publicado em: 2020-05
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23. Determinação de docetaxel e metabólitos em plasma por UPLC-MS/MS: desenvolvimento de metodologia analítica e aplicação clínica
A highly sensitive ultra-performance liquid chromatography tandem mass spectrometry method for the determination of Docetaxel and metabolites (M1+M3) in human plasma samples was developed and validated. The method employs a liquid-liquid extraction and a reversed phase separation Acquity® C18 column BEH C18 (150 x 2.1 mm, 1.7 µm). Mobile phase was a mixtur
Quím. Nova. Publicado em: 2020-04
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24. Application of a New Validated HPLC-PDA Method for Simultaneous Determination of Curcumin and Melatonin in Hyaluronic Acid-Coated Nanoemulsions
In this study, a high-performance liquid chromatography with photodiode array detector (HPLC-PDA) method was developed and validated to simultaneously determine curcumin (CUR) and melatonin (MEL) in hyaluronic acid-coated nanoemulsions, a novel targetable delivery system to CD44 receptors overexpressed in many types of tumors. Chromatographic analyses were p
J. Braz. Chem. Soc.. Publicado em: 2020-03