Ion Chromatography
Mostrando 1-12 de 1293 artigos, teses e dissertações.
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1. Development and application of a test mixture for untargeted liquid chromatography-mass spectrometry analysis of urine samples
Metabolic profiling of complex biological matrices based on liquid chromatography-mass spectrometry (LC-MS) allows detecting a wide range of metabolites with distinct concentrations and physicochemical properties. Given the complexity of samples and the necessity of a comprehensive approach in untargeted metabolomics, quality control strategies are mandatory
Química Nova. Publicado em: 2022
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2. A Systematic Pipeline to Enhance the Fecal Metabolome Coverage by LC-HRMS
The comprehended knowledge of the metabolic profile of the fecal matter has been recognized as an important point for understanding metabolic changes in the human systemic metabolism and it can provide precious information about host-gut microbiota interactions. However, few analytical strategies have been addressed for a broad analysis of metabolites with d
J. Braz. Chem. Soc.. Publicado em: 2021-07
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3. In vitro metabolism of copalic and kaurenoic acids in rat and human liver microsomes
Copalic (CA) and kaurenoic (KA) acids are the main diterpenes found in the oleoresin extracted from the copaiba tree (Copaifera sp). This study aimed to characterize the metabolism of CA and KA in rat and human liver microsomes using liquid chromatography with tandem mass spectrometry (LC-MS/MS). The in vitro assays showed deviations from the Michaelian kine
Quím. Nova. Publicado em: 2021-06
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4. Avaliação da concentração e composição inorgânica do material particulado coletado no estado do Rio de Janeiro
Cities urbanization and modernization increase emission sources, contributing to particulate matter (PM) composition heterogeneity and enhance the risk to human health and environment. This paper intends to survey the studies on particulate matter carried out in the state of Rio de Janeiro. The sampling of PM is generally made using Hi-Vol samplers to collec
Quím. Nova. Publicado em: 2021-06
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5. Structural characterization and bioactivities of a polysaccharide from the stalk residue of Pleurotus eryngii
Abstract The structural characterization and bioactivities of a polysaccharide from the stalk residue of Pleurotus eryngii were investigated. Firstly the stalk residue of P. eryngii was collected from the top portion of spent mushroom substrate and processed to yield water-soluble polysaccharide. Subsequently this crude polysaccharide was purified by DEAE Se
Food Sci. Technol. Publicado em: 2020-06
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6. Geochemical Investigation of Tar Balls Collected in a Brazilian Beach Using Biomarkers, Ni/V, δ13C Ratios and Ultra-High Resolution FT-ICR Mass Spectrometry
Representative tar balls collected in two distinct years (2012 and 2014) in a beach along the State of Bahia, northeastern Brazil, were geochemically characterized in order to identify correlations between them and investigate potential sources. Terpanes and steranes biomarkers (detected by gas chromatography coupled to mass spectrometry, GC-MS), carbon stab
J. Braz. Chem. Soc.. Publicado em: 2020-04
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7. A Selective Gas Chromatography-Selected Ion Monitoring Mass Spectrometry (GC-MS/SIM) Method to Determine Polychlorinated Biphenyls in Fuller’s Earth
Polychlorinated biphenyls (PCBs) are carcinogenic to humans and can be found in Fuller’s earth used for the regeneration of used transformer oil. This work describes a highly selective gas chromatographic-selected ion monitoring mass spectrometric method (GC-MS/SIM) for the simultaneous determination of three Aroclor PCB congener mixtures (1242, 1254, and
J. Braz. Chem. Soc.. Publicado em: 2020-03
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8. Development and Validation of a UPLC-ESI-MS Method for Quantitation of the Anti-Alzheimer Drug Galantamine and other Amaryllidaceae Alkaloids in Plants
Our study aimed at the development of a method based on ultra-performance liquid chromatography coupled to mass spectrometry (UPLC-ESI-MS) using selected ion monitoring for the simultaneous quantitation of the alkaloids galantamine, pseudolycorine, sanguinine and narciclasine in Amaryllidaceae species (Hippeastrum elegans, Habranthus cf. irwinianus, Hymenoca
J. Braz. Chem. Soc.. Publicado em: 2020-02
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9. Halogen Determination in Polymeric Waste of Electrical and Electronic Equipment: Overcoming Limitations in Sample Preparation
Sample preparation of polymers for halogen determination requires special attention because they are difficult to bring into solution and due to the risk of analyte losses when using acid digestion. A method using microwave-induced combustion (MIC) was optimized for accurate determination of halogens in polymeric parts obtained in waste of electrical and ele
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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10. Chlorine and Fluorine Determination in Eye-Pencil: Development of an Eco-Friendly Sample Preparation Method for Ion Chromatography Analysis
In this paper, a feasible method was proposed for the chlorine and fluorine determination in eye-pencil samples using ion chromatography (IC). The microwave-induced combustion (MIC) was used to digest up to 200 mg of a sample, with 50 mg of microcrystalline cellulose as a combustion aid and only water for analytes absorption. Cl and F recoveries were 105 ±
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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11. Direct Assay to Evaluate Phosphoenolpyruvate Carboxykinase Activity
Phosphoenolpyruvate carboxykinase (PEPCK) is a ubiquitous enzyme found in all known groups of organisms, acting in the reversible conversion of oxaloacetate (OAA) to phosphoenolpyruvate (PEP) in the presence of divalent metal ion, and dependent of adenosine 5’-triphosphate (ATP) or guanosine-5’-triphosphate (GTP). PEPCK is an important enzyme in the meta
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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12. 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