Related Experiment Video
Updated: Aug 17, 2026

Synthesis and Purification of Iodoaziridines Involving Quantitative Selection of the Optimal Stationary Phase for Chromatography
Published on: May 16, 2014
Titanized silicas, modified by C18, as promising stationary phases for high pH separations
César R Silva1, Claudio Airoldi, Kenneth E Collins
1Instituto de Química, Universidade Estadual de Campinas, Caixa Postal 6154, 13084-971 Campinas, São Paulo, Brazil.
Abstract:
To enhance the high pH stability of silica based reversed phases, chemically bonded octadecyl phases were prepared through silanization of titanized silica particles containing approximately 14% titanium oxide on the surface. The present work describes some spectroscopic characterizations using infrared, solid-state 13C and 29Si nuclear magnetic resonance (NMR) and X-ray absorption spectroscopy (XAS). Chromatographic characterizations for the titanized phase as well as for a conventional C18 phase, based on the same silica support without titanization, are also described using three different test mixtures containing neutral, polar and basic compounds. After an artificial stability test at pH 10, the titanized phase was again characterized by elemental and X-ray fluorescence analyses to determine the remaining carbon and titanium contents. As an application to real world samples, the separation of some herbicides and highly basic drugs using buffered mobile phases are also shown.
Related Concept Videos
High-Performance Liquid Chromatography: Introduction
In HPLC, two phases play a critical role in the separation process:
Silica Gel Column Chromatography: Overview
Polar components tend to bind strongly to the silica gel, causing them to move slowly through the column. In contrast, nonpolar compounds...
Gas Chromatography: Types of Columns and Stationary Phases
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
Size-Exclusion Chromatography
Silica particles offer advantages such as rigidity,...
Optimizing Chromatographic Separations
Band broadening refers to spreading solute bands as they travel through the column. This broadening can impact resolution. Plate height (H) represents the length required for one theoretical plate. A lower plate height corresponds to...
Thin-Layer Chromatography (TLC): Overview
To begin the analysis, a mixture of compounds is spotted on the starting line on the TLC plate using a thin capillary. The bottom of the...
