Recent Developments in Type C Stationary Phases: Exploiting the Versatility of Silica Hydride Materials - Joseph J. Pesek

TYPE C™ silica is a relatively new chromatographic material that has been finding ever-increasing use in the last few years. The properties exhibited by these stationary phases are often significantly different than the ordinary silica used for most commercial products. While all TYPE C phases can be utilized in the reversed-phase, organic normal phase and aqueous normal phase modes, there are some unique capabilities within each retention mode that have resulted in innovative method development strategies with great success. Some of the more challenging separation problems involve polar compounds; two approaches for the analysis of hydrophilic compounds are described in this report.

Introduction
TYPE C silica, based on a surface of Si-H, was introduced many years ago. However, it has only been recently that some of the unique chromatographic features of this material have been discovered and exploited in
solving challenging separation problems. This report focuses on the capabilities of these stationary phases for the separation of hydrophilic materials in two modes: aqueous normal phase (ANP) that utilizes high organic
content mobile phases and in reversed-phase using high aqueous content mobile phases. For descriptions about the chromatographic properties of TYPE C in the organic normal phase, earlier reports have provided
examples of separations utilizing this separation mechanism [1,2].