Analytical Sciences

Abstract − Analytical Sciences, 14(2), 361 (1998).

Effect of the Type of Organic Modifiers on Mass Transfer in Reversed-Phase Liquid Chromatography
Kanji MIYABE * and Shigeya TAKEUCHI
Chemistry Section, Faculty of Education, Toyama University, Gofuku, Toyama 930, Japan
The mass-transfer characteristics were studied in a reversed-phase liquid chromatography consisting of an octadecylsilyl-silica gel and acetonitrile/water mixture (70/30, vol), and were compared with those obtained by using methanol/water (70/30, vol). In the two chromatographic systems, similar tendencies were observed for various adsorption characteris-tics. However, their absolute values were not entirely identical. Irrespective of the type of organic modifiers, surface dif-fusion was dominant for intraparticle diffusion. Similar correlations were also demonstrated with regard to the surface diffusion, i.e., the enthalpy-entropy compensation and the linear free-energy relation, suggesing a similarity in the surface migration mechanism in the two chromatographic systems. A few estimation procedures of the surface diffusion coeffi-cient were proposed. (Keywords: Liquid chromatography, reversed-phase mode, mass transfer, surface diffusion, organic modifier)