Thin-layer chromatography of phenolic acids on aminopropylsilica

The possibility of using aminopropylsilica TLC plates for determination of phenolic acids has been investigated. Eighteen phenolic acids were chromatographed on aminopropyl-bonded silica with mobile phases comprising mixtures of diisopropyl ether and acetic acid with toluene, petroleum ether, or heptane. The selectivity of the proposed chromatographic systems was satisfactory. The best separations were obtained with heptane-diisopropyl ether-acetic acid, 4 + 5 + 1 ( v / v ) or petroleum ether-diisopropyl ether-acetic acid, 6 + 3 + 1 ( v / v ) as mobile phase.