Brandon Salazar

A newly developed stationary phase based on p-phenylenediamine (PPD) grafted onto superficially porous silica particles via diazonium chemistry, was synthesized under various experimental conditions. The PPD-derived phase was characterized via diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) and elemental analysis (EA). X-ray photoelectron spectroscopy (XPS) was also used in order to gain insight into the surface chemistry of the modified silica. The PPD-modified silica displays a series of phenyl groups as well as amine functionalities at the surface. In addition to effect separation, the amine groups at the surface of this material can serve as a platform for further functionalization, which can provide a means to fabricate columns with desired chromatographic selectivity. A preliminary chromatographic assessment of the material demonstrated its potential applicability in both reversed-phase and hydrophilic interaction liquid chromatography (HILIC). The phenylene-like material also showed good hydrolytic stability when exposed to acidic conditions and a temperature of 80°C.