9-Methyl Acridine modified silica as Mixed-Mode Stationary Phase of High-Performance Liquid Chromatography for a Wide Range Separation of Compounds

The development of novel stationary phases with high separation efficiency has always been the focus point of study. Mixed-mode stationary phases have been proved to be with the merits of a wide range separation of materials [1]. In this work, a stationary phase mixed-mode was prepared from 9-methyl acridine embedded on silica surface to create a multiple separation mechanism in the chromatography column. The 9-methyl acridine was synthesized from diphenylamine, acetic acid in the presence of zinc chloride catalyst. The material was purified by column chromatography [2]. In the making of the stationary phase, the 3-chloro propyl trimethoxysilane was reacted with silica. After completion of the reaction and washing, the excess amount of all methoxyl groups on the silica surface was hydrolyzed using water and replaced with chloro trimethylsilane. Finally, the product made of 9-methyl acridine, is subjected to a reaction with a chlorinated reagent on silica [3]. Since the stationary phase has several effective groups, there will be a multiple interaction mechanism (eg π-π, ion exchange, hydrophobic, etc.) between the analytes and the stationary phase. This stationary phase is used to separate samples with different polarity.