https://repositorio.ufba.br/handle/ri/8324
metadata.dc.type: | Artigo de Periódico |
Title: | Sensitive spectrophotometric determination of ascorbic acid in fruit juices and pharmaceutical formulations using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP) |
Other Titles: | Fresenius' Journal of Analytical Chemistry |
Authors: | Ferreira, Sergio Luis Costa Bandeira, Marcus Luciano Souza de Ferreira Lemos, Valfredo Azevedo Santos, Hilda Costa dos Costa, Antonio Celso Spinola Jesus, Djane S. de |
metadata.dc.creator: | Ferreira, Sergio Luis Costa Bandeira, Marcus Luciano Souza de Ferreira Lemos, Valfredo Azevedo Santos, Hilda Costa dos Costa, Antonio Celso Spinola Jesus, Djane S. de |
Abstract: | A simple and very sensitive method has been developed for the determination of ascorbic acid based on the oxidation of ascorbic acid to dehydroascorbic acid by iron(III), followed by a complexation of iron(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol(Br-PADAP). The iron(II) complex is formed immediately, with absorption maxima at 560 and 748 nm and a molar absorptivity of 1.31 × 105 l mole–1cm–1 and 5.69 × 104 l mole–1cm–1, respectively. The ascorbic acid determination is possible with a linear range up to 2.4 μg ml–1, a calibration sensitivity of 0.744 ml μg–1 at 560 nm and 0.323 ml μg–1 at 748 nm, and a detection limit of 15 ng ml–1 and 44 ng ml–1, respectively. The procedure was used for the ascorbic acid determination in several fruit juices and pharmaceutical formulations. The results demonstrated a good precision (R.S.D. < 1%) and are in agreement with those obtained with others methods. The Br-PADAP method proposed is six times more sensitive than the method using the iron(II)-1,10-phenanthroline system. |
URI: | http://www.repositorio.ufba.br/ri/handle/ri/8324 |
Issue Date: | 1997 |
Appears in Collections: | Artigo Publicado em Periódico (Química) |
File | Description | Size | Format | |
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Ferreira.pdf Restricted Access | 58,93 kB | Adobe PDF | View/Open Request a copy |
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