Absorptivity
Mostrando 13-24 de 47 artigos, teses e dissertações.
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13. Metodologia analítica para determinação de esteróis fecais em sedimentos por Cromatografia Líquida de Alta Eficiência
The fecal sterols are considered important indicators of fecal contamination in aquatic environments. Organic compounds are hydrophobic and are associated with the particulate material and can be preserved for a long time with negligible degradation. The relationships between coprostanol and other sterols found in the environment are important to confirm the
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/05/2011
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14. ObtenÃÃo, caracterizaÃÃo e aplicaÃÃo de uma nova superfÃcie Seletiva para coletores solares tÃrmicos / Acquisition, Characterization and Application of a New Selective Surface for Solar Thermal Collectors
O estudo de superfÃcies seletivas para coletores solares tÃrmicos, hà alguns anos, enfoca o uso de pastas e tintas para recobrir chapas de cobre ou alumÃnio, formando a placa absorvedora do coletor. Essas tintas ou pastas sÃo eletrodepositadas em placas metÃlicas, sendo este processo muitas vezes responsÃvel pelo levado custo de superfÃcies seletivas
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/03/2011
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15. Development of a flotation-spectrophotometric method for determination of cetylpyridinium chloride in pharmaceutical products
A new simple and sensitive flotation-spectrophotometric method for the determination of cetylpyridinium chloride (CPC) is reported. The method is based on the formation of an ion- associate between CPC and Orange II (OR) which is floated in the interface of aqueous phase and n-hexane by vigorous shaking. The aqueous solution was discarded and the adsorbed io
Química Nova. Publicado em: 2011
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16. Alterações físico-químicas do óleo de palma na pré-fritura contínua de produtos cárneos empanados de frango - tipo "snacks"
The lack of time for the preparation of food has caused an increase in consumption of fried foods that are a rapid alternative of preparation that promotes sensory properties highly appreciated by consumers. The continuous frying method is used by the industrial market for pre frying procedures. Palm oil has high oxidative stability by having almost equivale
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/10/2010
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17. Spectrophotometric determination of nevirapine using tetrathiocyanatocobalt(II) ion as a reagent
A simple and rapid spectrophotometric method for the determination of nevirapine is described. The method is based on the reaction of nevirapine with tetrathiocyanatocobalt(II) ion in buffer of pH 4 to form the corresponding complex. Beer's law is obeyed in the range of 0.2 - 2.0 µg mL-1 for nevirapine. The optical parameters such as molar absorptivity, San
Eclética Química. Publicado em: 2010-09
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18. Development and validation of spectrophotometric method for the determination of DPP-4 inhibitor, sitagliptin, in its pharmaceutical preparations
A simple, sensitive and reproducible spectrophotometric method was developed for the determination of sitagliptin phosphate in bulk and in pharmaceutical formulations. The proposed method is based on condensation of the primary amino group of sitagliptin phosphate with acetyl acetone and formaldehyde producing a yellow colored product, which is measured spec
Eclética Química. Publicado em: 2010-09
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19. New reagents for the spectrophotometric determination of ranitidine hydrochloride
A new spectrophotometric method is proposed for the assay of ranitidine hydrochloride (RNH) in bulk drug and in its dosage forms using ceric ammonium sulphate (CAS) and two dyes, malachite (MAG) green and crystal violet (CV) as reagents. The method involves the addition of a known excess of ceric ammonium sulphate to ranitidine hydrochloride in acid medium,
Eclética Química. Publicado em: 2010-09
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20. Selective and non-extractive spectrophotometric determination of cefdinir in formulations based on donor-acceptor complex formation
Cefdinir has broad spectrum of activity and high prescription rates, hence its counterfeiting seems imminent. We have proposed a simple, fast, selective and non-extractive spectrophotometric method for the content assay of cefdinir in formulations. The method is based on complexation of cefdinir and Fe under reducing condition in a buffered medium (pH 11) to
Química Nova. Publicado em: 2010
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21. Determinação espectrofotométrica de cefalexina em formulações farmacêuticas explorando a sua reação de transferência de carga com a quinalizarina
This work proposes a new simple and fast spectrophotometric method for cephalexin determination in pharmaceutical formulations. The method is based on the charge transfer reaction between cephalexin and quinalizarin in dimethylsulfoxide medium. Several analytical parameters related to the system were optimized and the reaction was characterized in terms of s
Química Nova. Publicado em: 2010
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22. Desenvolvimento e otimização de metodologia para análise de edulcorantes por Eletroforese Capilar
An innovative methodology was developed to simultaneously separate and quantify aspartame, cyclamate, saccharin and acesulfame-K through capillary electrophoresis with direct and indirect detection of UV, analysis time of roughly 6 minutes and with no sample derivatization. As the cyclamate has low absorptivity we used a system of electrolyte added to a chro
Publicado em: 2010
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23. Sensitive spectrophotometric determination of lamotrigine in bulk drug and pharmaceutical formulations using bromocresol green
Two new, simple, rapid and reproducible spectrophotometric methods have been developed for the determination of lamotrigine (LMT) both in pure form and in its tablets. The first method (method A) is based on the formation of a colored ion-pair complex (1:1 drug/dye) of LMT with bromocresol green (BCG) at pH 5.02±0.01 and extraction of the complex into dichl
Eclética Química. Publicado em: 2010
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24. DESENVOLVIMENTO, OTIMIZAÇÃO E VALIDAÇÃO DE METODOLOGIAS POR ELETROFORESE CAPILAR PARA ANÁLISE DE FÁRMACOS UTILIZADOS NO TRATAMENTO DA TUBERCULOSE
The main focus of this thesis was the development, optimization and validation of analytical methodologies for analysis of pharmaceutical preparations used for tuberculosis treatment, which contain as active ingredients, ethambutol (ETB), isoniazid (ISO), rifampicin (RIF) and pyrazinamide (PYR) isolated or in association. Two analytical methodologies for ETB
Publicado em: 2010