Photodiode
Mostrando 1-12 de 76 artigos, teses e dissertações.
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1. CONSTRUCTION OF A LOW-COST POLARIMETER FOR EDUCATIONAL PURPOSES
This paper describes the construction of a polarimeter for the identification of chemical substances. The device was built with low-cost materials, measures the phenomenon of optical activity and has educational applicability. The measurement of optical activity is achieved through the measurement of the resulting polarized radiation in a photodiode connecte
Quím. Nova. Publicado em: 2021-03
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2. A Facile Synthesized Polyaniline Coated Zerovalent Iron-Silica as an Efficient Sorbent for Magnetic Solid Phase Extraction of Phenolic Pollutants in Water Samples
A magnetic material based on polyaniline coated zerovalent iron-silica (Fe@SiO2@PANI) was simply synthesized using a facile manner under low energy consumption and applied for magnetic solid phase extraction of phenolic pollutants prior to analysis by high performance liquid chromatography-photodiode array detection (HPLC-PDA). The parameters which affected
J. Braz. Chem. Soc.. Publicado em: 2021-01
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3. 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
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4. The role of seasonality on the chemical composition, antioxidant activity and cytotoxicity of Polish propolis in human erythrocytes
ABSTRACT Propolis extracts possess beneficial biological effects, such as antioxidant activity. However, the composition of propolis and biological properties of its extracts depend on many factor, including time of harvesting. The main purpose of this study was to evaluate the seasonal effect on the phenolic profile of Polish propolis extracts and their ant
Rev. bras. farmacogn.. Publicado em: 26/08/2019
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5. Rapid quantitative analysis of six flavonoids in licorice by ultra-performance convergence chromatography
Abstract Objective This study was to establish a rapid quantitative method for determination of six characteristic flavonoids, including licochalcone A (1), liquiritigenin (2), glabridin (3), isoliquiritigenin (4), liquiritoside (5), and isoliquiritoside (6) in licorice by a ultra-performance convergence chromatography (UPC2) apparatus equipped with a phot
Food Sci. Technol. Publicado em: 11/04/2019
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6. Development and Validation of a Rapid and Reliable RP-HPLC-PDA Method for the Quantification of Six Diterpenes in Copaifera duckei, Copaifera reticulata and Copaifera multijuga Oleoresins
Oleoresins from Copaifera species are extensively used in folk medicine in Brazil, which are employed mainly in the production of cosmetic formulations in Brazil, North America and Europe. Considering the lack of validated analytical methods for the analyses of diterpenes in Copaifera oleoresins, it was developed a validated and reliable reversed-phase high-
J. Braz. Chem. Soc.. Publicado em: 2018-04
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7. Turbo-extraction of glycosides from Stevia rebaudiana using a fractional factorial design
ABSTRACT Stevia rebaudiana (Bertoni) Bertoni, Asteraceae, leaf extract has recently called the attention of food industry as a proposal for natural sweetener. The sweet flavor is attributed to the glycosides, in especial stevioside and rebaudioside A, which are the plant main chemical markers. The aim of the work reported here was to optimize the turbo-extra
Rev. bras. farmacogn.. Publicado em: 2017-08
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8. Inhibitory effect of the Pseudobrickellia brasiliensis (Spreng) R.M. King & H. Rob. aqueous extract on human lymphocyte proliferation and IFN-γ and TNF-α production in vitro
Pseudobrickellia brasiliensis (Asteraceae) is a plant commonly known as arnica-do-campo and belongs to the native flora of the Brazilian Cerrado. The alcoholic extract of the plant has been used as an anti-inflammatory agent in folk medicine, but the biological mechanism of action has not been elucidated. The present study evaluated the composition of P. bra
Braz J Med Biol Res. Publicado em: 10/07/2017
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9. Direct Determination of N-Nitrosoglyphosate in Technical Glyphosate Using Ion Chromatography with UV Detection
The official method for analyzing N-nitrosoglyphosate (NNG), a relevant impurity, in glyphosate matrix demands complicated instrumentation and operating conditions not available in many laboratories. In this work, we developed a direct, simple, selective and sensitive ion chromatography (IC) method with UV detection for the determination of NNG in samples of
J. Braz. Chem. Soc.. Publicado em: 2017-07
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10. A stability-indicating HPLC-PDA method for the determination of ferulic acid in chitosan-coated poly(lactide-co-glycolide) nanoparticles
ABSTRACT The development and validation of a simple and efficient method for the quantification of ferulic acid in poly (D,L-lactide-co-glycolide) (PLGA) nanoparticles coated with chitosan (CS) by reverse phase high performance liquid chromatography coupled to photodiode array detection was described. For the chromatographic analysis, a reverse phase C-18 co
Braz. J. Pharm. Sci.. Publicado em: 22/06/2017
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11. Simultaneous determination of atorvastatin and ezetimibe from combined pharmaceutical products by micellar electrokinetic capillary chromatography
Abstract A rapid and sensitive micellar electrokinetic capillary chromatography method with UV photodiode-array detection was developed for the simultaneous determination of atorvastatin and ezetimibe in fixed dose drug combination. Experimental conditions such as buffer concentration and pH, surfactant concentration, system temperature, applied voltage, inj
Braz. J. Pharm. Sci.. Publicado em: 20/04/2017
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12. Rapid identification and quantitative analysis of chemical constituents of Gentiana veitchiorum by UHPLC-PDA-QTOF-MS
ABSTRACT Gentiana veitchiorum Hemsl., Gentianaceae, a traditional Tibetan medicine, was used for the treatment of liver jaundice with damp-heat pathogen, as well as for headache and chronic pharyngitis. A rapid ultra-performance liquid chromatography, photodiode array detector, quadrupole time-of-flight mass spectrometry method was developed for the fast and
Rev. bras. farmacogn.. Publicado em: 2017-04