J. Barbosa et al., PREFERENTIAL SOLVATION IN ACETONITRILE-WATER MIXTURES - RELATIONSHIP BETWEEN SOLVATOCHROMIC PARAMETERS AND PK VALUES OF CARBOXYLIC-ACIDS, Journal of the Chemical Society. Faraday transactions, 93(10), 1997, pp. 1915-1920
Citations number
38
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
Ionization constants of several carboxy!ic acids in acetonitrile-water
mixtures, usually used as mobile phases in liquid chromatography (LC)
, have been obtained in order to predict the influence of pH on retent
ion and selectivity in LC. In this work, the quasi-lattice quasi chemi
cal (QLQC) theory of preferential solvation was applied to obtain the
degree of preferential solvation of acetate ions in these media in ord
er to explain the variation of the pK values obtained over the whole c
omposition range studied. Also, the relationships between pK values an
d various macroscopic and microscopic properties were used to calculat
e pK values of the carboxylic acids in any acetonitrile-water mixture
up to 70% (w/w) and, thus, to determine the acid-base behaviour of sub
stances in the widely used acetonitrile-water media.