Evaluation of protein, peptide, and amino acid retention on C5 hydride-based stationary phases

A pentyl (C5) stationary phase is synthesized on a hydride surface using both 100 and 300 A silica particles. The aqueous normal phase properties of these new phases are evaluated using amino acids at high concentrations of ACN in the mobile phase containing 0.1% formic acid. The RP properties of the materials are tested by using peptides and proteins in order to evaluate the effect of pore size on retention. Comparisons of retention as well as efficiencies and peak symmetry with a C18 phase are used to determine the influence of the hydrophobic properties of the bonded material. An evaporative light scattering detector (ELSD) is used in all phases of the study and compared with UV detector for gradient elution of proteins.