Derivatization
Mostrando 1-12 de 230 artigos, teses e dissertações.
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1. Innovative gas chromatographic determination of formaldehyde by miniaturized extraction and on-fiber derivatization, via SPME and SPME Arrow
Formaldehyde (FA) is a carbonyl compound, ubiquitous in the environment and among the most widespread pollutants: it has exhibited toxic properties and is classified as a human carcinogen. FA is released from several sources, both temporary (e.g., combustion processes) and permanent (e.g., building products). This work proposes an innovative fully-automated
Química Nova. Publicado em: 2022
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2. ATIVIDADE ANTIMICROBIANA DE QUITOSANAS E SEUS DERIVADOS: INFLUÊNCIA DAS CARACTERÍSTICAS ESTRUTURAIS
In recent years, there has been an increasing interest in the development of antimicrobial materials for different applications, especially in the biomedical field. In this context, chitosan is one of the most employed materials due to its highly attractive properties, such as biocompatibility, biodegradability, non-toxicity, and antimicrobial activity again
Química Nova. Publicado em: 2022
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3. Use of Direct Aqueous Injection and Solid Phase Extraction Coupled with Hydrophilic Interaction Chromatography to Analyze Haloacetic Acids in Drinking Water Samples
In this study, two analytical methods were evaluated to determine haloacetic acids (HAAs) in drinking water samples. Direct aqueous injection (DAI) and solid phase extraction (SPE) were evaluated and determination was performed by liquid chromatography tandem mass spectrometry (LC-MS/MS) with a hydrophilic interaction chromatography (HILIC) analytical column
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Development and Validation of a Gas Chromatographic Method for the Quantification of Minor Alkaloids in Cocaine
The quantification of minor alkaloids in seized cocaine can provide information for drug profiling and law enforcement initiatives. This work presents the development and validation of an analytical method to quantitate minor alkaloids in cocaine samples using gas chromatography with flame ionization detector, after derivatization. The method was validated i
J. Braz. Chem. Soc.. Publicado em: 2021-04
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5. Bergenin of Peltophorum dubium (Fabaceae) Roots and Its Bioactive Semi-Synthetic Derivatives
This work describes the isolation of pure bergenin from Peltophorum dubium roots with good yields and its further derivatization through Williamson synthesis. The alkyl derivatives of the bergenin were identified by nuclear magnetic resonance and mass spectrometry data analysis. Among them, three derivatives were reported for the first time herein, 8,10-dihe
J. Braz. Chem. Soc.. Publicado em: 2020-12
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6. SYNTHESIS AND PHYTOTOXIC PROFILE OF A NEW TETRAOXANE DESIGNED FROM A COMMERCIAL AUXIN
Modern agriculture relies on the massive use of agrochemicals, including herbicides. Despite their effectiveness, a continuous use of herbicides sharing the same target has resulted in the selection of weed biotypes resistant to such chemicals. To cope with this problem, the development of new herbicides is an urgent requirement. In this work we applied the
Quím. Nova. Publicado em: 20/07/2020
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7. Determination, through Derivatization and GC-MS Analysis, of Omega-3 and Omega-6 Fatty Acids in Fish Oil Capsules Sold in Salvador, Bahia
The essential w-3 and w-6 fatty acids have important physiological functions, such as prevention of cardiovascular diseases and atherosclerosis, and are commercially sold as fish oil capsules. In the present work, a method previously described in the literature, based on the derivatization of polyunsaturated fatty acids and their gas chromatography-mass spec
J. Braz. Chem. Soc.. Publicado em: 2020-03
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8. Quantification of Glyphosate and AMPA by HPLC-ICP-MS/MS and HPLC-DAD: A Comparative Study
In this work, the direct determination methodology of glyphosate and aminomethylphosphonic acid (AMPA) by high performance liquid chromatography (HPLC) using inductively coupled plasma with triple quadrupole mass spectrometer (ICP-MS/MS) was compared with the conventional method using diode array detector (HPLC-DAD). Both methods were selective, but the chro
J. Braz. Chem. Soc.. Publicado em: 2020-02
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9. GC–MS and LC–MS/MS workflows for the identification and quantitation of pyrrolizidine alkaloids in plant extracts, a case study: Echium plantagineum
Abstract Workflows based on gas and liquid chromatography coupled to mass spectrometry for the identification of toxic pyrrolizidine alkaloids present in plants were developed and applied to Echium plantagineum L., Boraginaceae, extracts. GC–MS based determinations need reduction and derivatization steps prior to MS analysis, which is performed using a Ful
Rev. bras. farmacogn.. Publicado em: 17/10/2019
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10. Rapid and Effective Sample Cleanup based on Polyvinylpyrrolidone-Coated Magnetite Nanoparticles Coupled with New Pre-Column Derivatization for Determination of Aflatoxins B1, B2, G1 and G2 in Animal Feeds by High-Performance Liquid Chromatography with Fluorescence Detection
A novel method for the determination of aflatoxins B1, B2, G1, and G2 (AFB1, AFB2, AFG1, AFG2) in animal feed samples based on magnetic solid-phase cleanup and novel pre-column derivatization has been developed. In this work, synthesized polyvinylpyrrolidone-coated Fe3O4 magnetic nanoparticles were applied as adsorbents for rapid cleanup for extracts of anim
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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11. ENDOPHYTIC FUNGI FROM THE BRAZILIAN FLORA AND THEIR EMPLOYMENT IN BIOTRANSFORMATION REACTIONS
The biotransformation reactions are used as a successful alternative to derivatization by the traditional chemistry because they conduct to uncommon reactions, which would hardly be carried out by chemical synthesis. A wide diversity of compounds may be metabolized by fungi, leading to chemical derivatives through selective reactions that work under ecofrien
Quím. Nova. Publicado em: 26/08/2019
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12. Fatty Acid Determination in Fermented Milk Samples Employing Direct Esterification and Gas Chromatography
The developed method (DM) allows to perform experiments in shorter time with reduced amount of sample and reagent for fatty acids (FA) determination in fermented milk samples. Design Expert software was employed to discover the greatest sonication time (7 and 20 min) and concentration for alkaline and acidic reactions (0.70 and 1.5 mol L-1). Validation proce
J. Braz. Chem. Soc.. Publicado em: 04/07/2019