SORPTION OF ACIDS, AND FORMATION OF HYDROGEN ION AND ANION FRONTS ON A THIN LAYER

Abstract

The behavior of acids on the layers of cellulose and silica gel was studied. The samples used were HCl and HClO₄, and the developers were water, acetone, ethanol, and n-butanol. Monitored, was also the behavior of HCl as a component of the developers water-HCl and n-butanol-HCl. The results have shown that acids are strongly sorbed on the layers of silica gel and cellulose. Hydrogen ion and an anion of strong inorganic acids behaved differently on sorbent layer; generally H⁺ ion was stronger sorbed than A⁻ ion. Sorption and behavior of acid ions depended on the properties of a sorbent, solvent and acid, i. e. on an interaction of all components of the chromatographic system.

Developers with a low content of a strong acid formed on the chromatogram two or three fronts: F_solvent, F_A ⁻ and F_H ⁺, and two or three areas of different composition of a developer and sorbed ions, in which areas there was a gradient of H⁺ and A⁻concentration. Weak acids were bound to the layer as molecules and could produce a second front (F_HA) only.

Acknowledgments