Pdms
Mostrando 1-12 de 140 artigos, teses e dissertações.
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1. In vivo and in vitro Volatile Constituents of the Flowers of Xylopia aromatica by HS-SPME/GC-MS
Xylopia aromatica (Lam.) Mart. (Annonaceae) is a typical species from the Brazilian cerrado that presents medicinal properties. The plant is distinguished by its large white flowers which produce a pleasant fragrance. X. aromatica is characterized by a wide range of medicinal application. These characteristics have motivated us to investigate the flowers vol
J. Braz. Chem. Soc.. Publicado em: 2021-05
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2. Optimization of a headspace solid-phase microextraction method for the gas chromatography-mass spectrometry analysis aroma compounds of Litsea mollis Hemsl. immature fruit
Abstract This study optimized using a headspace solid-phase microextraction (HS-SPME) method for extracting volatile aroma compounds, terpenoids in particular, from Litsea mollis Hemsl. immature fruit (LMIF). Gas chromatography-mass spectrometry was used to separate and identify volatile terpenoids in LMIF. The types of SPME fiber coating, salt addition, and
Food Sci. Technol. Publicado em: 2020-12
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3. OTIMIZAÇÃO DO PROCESSO NÃO INVASIVO E NÃO DESTRUTIVO DE EXTRAÇÃO E ANÁLISE DE METABÓLITOS VOLÁTEIS DE MAMÃO PAPAIA POR SPME-GC-MS
The analysis of volatiles is an alternative in the routine of quality control of fruits, since the volatile metabolites can change in the presence of microorganisms. A well-established method for extracting volatiles is the solid phase microextraction (SPME). This work aims to define some parameters (fiber coating, conditioning time and fiber exposure time)
Quím. Nova. Publicado em: 2020-09
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4. Optimization of extraction conditions of volatile compounds of roasted beef by solid-phase microextraction
Aroma is one of the most important sensory attributes for acceptance by beef consumers. The first step in analysing the volatile compounds associated with this attribute is their extraction from the food matrix, solid-phase microextraction has been widely used for volatile compound determination in meat. This study aimed to test six different solid-phase mic
Quím. Nova. Publicado em: 2020-04
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5. SBSE(EG-Silicone)-UFLC-MS/MS and HPLC-Flu Analysis of Norharman in Passiflora edulis Rinds
Previous studies on Passiflora edulis (sour passion fruit) rinds reported some biological activities and there is a growing interest on rinds flour as a possible functional food, but its alkaloid composition was not detailed investigated. This work reports on for the first time in the literature the identification of norharman in P. edulis rinds, by using st
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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6. Uncured Polydimethylsiloxane as Binder Agent for Carbon Paste Electrodes: Application to the Quantification of Propranolol
This study describes the use of uncured polydimethylsiloxane (PDMS) as a binder agent to prepare carbon paste electrodes (CPEs). A comparative study between the properties of CPEs prepared with PDMS and mineral oil Nujol®, the most common binder agent for CPEs, was carried out. Cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometr
J. Braz. Chem. Soc.. Publicado em: 16/09/2019
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7. Evaluation of the Influence of Extraction Conditions on the Isolation and Identification of Volatile Compounds from Cagaita (Eugenia dysenterica) Using HS-SPME/GC-MS
The objective of this study was to explore the extraction and identification of volatile organic compounds (VOCs) present in cagaita fruit (Eugenia dysenterica). Parameters such as type of extraction fiber, agitation, extraction time and extraction temperature were investigated. Initially, the VOCs were extracted using headspace solid-phase microextraction.
J. Braz. Chem. Soc.. Publicado em: 2019-02
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8. SPME Fiber Evaluation for Volatile Organic Compounds Extraction from Acerola
Volatile organic compounds (VOCs) were isolated from acerola fruits (Malpighia emarginata D.C.), by means of different solid phase microextraction (SPME) fibers. For the extraction, the headspace SPME method was used, identifying the VOCs by gas chromatography (GC) with mass spectrometry (MS). The objective of this work was to evaluate the efficiency of SPME
J. Braz. Chem. Soc.. Publicado em: 2019-02
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9. Electrode Material Containing Graphite Incorporated to an Amino-Functionalized Polydimethylsiloxane Network for the Detection of Copper
Graphite was incorporated to a polydimethylsiloxane (PDMS) polymer network functionalized with amino groups to obtain an electrode material and used to detect copper ions in aqueous solutions and sugarcane spirit. The polymer network was prepared with PDMS, 3-aminopropyl-trimethoxysilane (APTMS), tetraethyl orthosilicate (TEOS) with addition of graphite to o
J. Braz. Chem. Soc.. Publicado em: 2018-08
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10. Using Bio-Replicated Forming Technologies to Fabricate Shark-Skin Surface
ABSTRACT Shark-skin surfaces show the non-smoothness characteristics due to the presence of riblet structures. In this work, biomimetic shark-skins were prepared by means of different bio-replicated forming techniques. These techniques include the PDMS elastomeric stamping method (e.g., PES method) and the PDMS embedded-elastomeric stamping method (e.g., PEE
Braz. arch. biol. technol.. Publicado em: 14/06/2018
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11. Targeted-Analysis of β-Carboline Alkaloids in Passionfruit (“Maracujá”) by SBSE(PDMS)-LC/Flu and UHPLC-MS
Samples of pulp and seeds of sour (P. edulis) and sweet (P. alata) passionfruit were subjected to targeted analysis to identify β-carboline alkaloids, using combined UHPLC-MS (ultrahigh performance liquid chromatography-mass spectrometry) and SBSE(PDMS) (stir bar sorption extraction using polydimethylsiloxane as stationary phase) for sample preconcentration
J. Braz. Chem. Soc.. Publicado em: 2018-04
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12. AVALIAÇÃO DO DESEMPENHO DE UMA FASE SENSORA DE POLIURETANO POR MEIO DA ENERGIA DE GIBBS DE SOLVATAÇÃO E ESPECTROSCOPIA DE INFRAVERMELHO PARA DETERMINAÇÃO DE TOLUENO EM ÁGUA
A novel sensing phase of polyurethane was predicted by quantum chemical calculations as capable of detecting toluene, with the experimental results revealing a limit of detection of 1.4 mg L-1 in the determination of toluene in water samples. The quantum chemical computational strategy was validated by assessing the impact of the polymer matrix sensing phase
Quím. Nova. Publicado em: 2018-04