Fast Gc
Mostrando 1-12 de 52 artigos, teses e dissertações.
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1. Determination of Ethyl Carbamate in Commercial Sweetened Sugar Cane Spirit by ESI-MS/MS Using Modified QuEChERS and 18-Crown-6/Trifluoroacetic Acid Spiking Additives
A fast, sensitive, and selective direct injection electrospray tandem mass spectrometry (DI ESI MS/MS) method that is able to quantify ethyl carbamate in commercial sweetened sugar cane spirit is described. The preparation method uses a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) with potassium carbonate added to sweetened sugar cane
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Fast Catalytic Pyrolysis of Tetradecanoic Acid: Formation of Ketones as Intermediate Compounds in the Production of Hydrocarbons
This work aimed to compare two different catalysts in the production of a long chain ketone, intermediate in the production of hydrocarbons, during pyrolysis of tetradecanoic acid as a model fatty acid. The studied variables were the temperature, 450 and 600 ºC, and catalysts, γ-Al2O3 and Nb2O5, the latter has never been studied under such conditions. Pyro
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Thermal and Catalytic Fast Pyrolysis of Oily Extracts of Microalgae: Production of Biokerosene
Three different microalgae species, Desmodesmus sp., Nannochloropsis oculata and Halamphora coffeaeformis were grown under controlled conditions. The resulting dry biomass was characterized by TG-DTA (thermogravimetry-differential thermal analysis) and extracted with three solvents having different polarities. The extracts gross mass yields varied from 2% us
J. Braz. Chem. Soc.. Publicado em: 2021-04
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4. SIMPLE AND FAST DETERMINATION FOR GAMMA-HYDROXYBUTYRATE (GHB) IN URINE SAMPLE BY LLE AND GC-MS
Gamma-hydroxybutyrate (GHB) is a depressant of the central nervous system able to promote disinhibition, anterograde amnesia and its use is related to Drug-Facilitated Crimes (DFC). Urine is the biological matrix of choice for toxicological analysis in victims of rape and/or theft in suspected victims of DFC. The aim of this work was the development of a sim
Quím. Nova. Publicado em: 2021-02
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5. Exploring Polypyrrole as Extraction Phase for Disposable Pipette Extraction Method for Multiclass Organic Micro-Pollutant Determination in River and Tap Water Using Gas Chromatography-Mass Spectrometry
The use of a polypyrrole (PPy) is described as an efficient extraction phase for disposable pipette extraction (DPX), in a fast and ruggedized analytical method for simultaneous determination of 18 organic micro-pollutants in water using gas chromatography-mass spectrometry (GC-MS). The DPX-blank pipettes were filled with PPy, a material produced through the
J. Braz. Chem. Soc.. Publicado em: 2020-10
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6. Fast and Ecological Liquid-Liquid Separation Method for Preparing Quinones Enriched Extract from Nigella sativa Oil
A fast, inexpensive, and ecological method based on liquid-liquid extraction principle has been developed for preparation of extract with high content of Nigella sativa (N. sativa) quinones. The gas chromatography-mass spectrometry (GC-MS) analysis showed that oil extraction using 70% ethanol for 6 h yielded extract containing 50% of thymoquinone (TQ) and 13
J. Braz. Chem. Soc.. Publicado em: 2020-04
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7. BIODIESEL SYNTHESIS FROM WASTE COOKING OIL USING A VARIETY OF WASTE MARBLE AS HETEROGENEOUS CATALYSTS
Abstract The research article is based on biodiesel synthesis by the transesterification of waste cooking oil with methanol in the presence of heterogeneous catalysts prepared from different marble. Eight samples of marble were successfully converted into potential catalysts by calcination. The thermal treatment of waste marbles at 300oC-1000oC converted the
Braz. J. Chem. Eng.. Publicado em: 13/01/2020
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8. Fast Triacylglycerol Screening and Semi-Quantitative Analysis of Fatty Acids in Commercial Oils by DIMS with 18-Crown-6 Ether/Trifluoracetic Acid Dopants
Vegetable oil analyses, especially due to the complexity of the oil components, are commonly laborious, requiring several analytical techniques. In this work, electrospray ionization mass spectrometry with direct injection (DIMS), along with 18-crown-6 ether (crown ether) chelating agent and trifluoroacetic acid (TFA), was used to characterize and semi-quant
J. Braz. Chem. Soc.. Publicado em: 2019-02
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9. Effects of in-office bleaching agent combined with different desensitizing agents on enamel
Abstract Objective: To analyze color change, microhardness and chemical composition of enamel bleached with in-office bleaching agent with different desensitizing application protocols. Materials and Methods: One hundred and seventeen polished anterior human enamel surfaces were obtained and randomly divided into nine groups (n = 13). After recording initi
J. Appl. Oral Sci.. Publicado em: 08/11/2018
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10. Detection of Counterfeit Durateston® Using Fourier Transform Infrared Spectroscopy and Partial Least Squares - Discriminant Analysis
Medicines containing anabolic steroids are one of the main targets for counterfeiting worldwide, including Brazil. The aim of this work was to propose a method for discriminating original and counterfeit Durateston® ampoules by Fourier transform infrared spectroscopy (FTIR) followed by chemometric analysis. Ninety-six ampoules of Durateston®, 49 originals
J. Braz. Chem. Soc.. Publicado em: 2017-07
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11. Chemical Constituents of Psychotria nemorosa Gardner and Antinociceptive Activity
Through dereplication strategies using gas chromatography-mass spectrometry (GC-MS) and ultra fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS), the ethanol extract from Psycotria nemorosa leaves (Rubiaceae) showed to be composed of: cinnamic acid, dihydroactinidiolide, 4-hydroxy-β-ionone, phytol, isophytol, 4,8,12,16-tetramethylheptadecan-4-
J. Braz. Chem. Soc.. Publicado em: 2017-05
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12. MICROEXTRAÇÃO LÍQUIDO-LÍQUIDO DISPERSIVA ASSISTIDA POR VORTEX E ULTRASSOM APLICADA À DETERMINAÇÃO DE AGROTÓXICOS TRIAZINAS, TRIAZINONAS E O TRIAZOL FLUTRIAFOL EM ÁGUA
This study aimed at developing and validating a method for the simultaneous determination of triazines (ametryne, atrazine, prometryne and terbuthylazine), triazinones (metribuzin and hexazinone) and a triazole (flutriafol) in water by ultrasound vortex assisted dispersive liquid-liquid microextraction (USVADLLME) and GC-MS. The experimental conditions that
Quím. Nova. Publicado em: 2016-09