Determination of Dissociation Constants of Some Hydroxylated Benzoic and Cinnamic Acids in Water from Mobility and Spectroscopic Data Obtained by CE-DAD
2009; American Chemical Society; Volume: 54; Issue: 3 Linguagem: Inglês
10.1021/je800595x
ISSN1520-5134
AutoresSabriye Perçin Özkorucuklu, J.L. Beltrán, G. Fonrodona, D. Barrón, Güleren Alsancak, José Barbosa,
Tópico(s)Electrochemical Analysis and Applications
ResumoIn this study, the dissociation constants of a series of phenolic acids, including benzoic acid, four hydroxylated derivatives (p-hydroxybenzoic, protocatechuic, vanillic, and gallic), and four hydroxylated cinnamic acid derivatives (p-coumaric, caffeic, ferulic, and sinapinic) have been determined in water by capillary electrophoresis (CE) from the electrophoretic mobilities at different pH value. The pKa values have also been obtained from the absorbance spectra at the maximum of the electrophoretic peaks, which were measured with a diode-array detector (CE-DAD methodology). The pKa values obtained from both methodologies (CE and CE-DAD) have been compared with those previously published in the literature and also with the values predicted by the SPARC online pKa calculator.
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