PROPYLAMIDO-MODIFIED C18 REVERSED-PHASE FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The synthesis and chromatographic properties of a propylamido-modified C18 stationary phase are described. The propylamido-modified C18 phase was prepared by bonding stearic acid to 3-aminopropyl-silica gel. The synthesis was simple and reproducible through amide formation by using N-hydroxysuccinimide and dicyclohexylcarbodiimide. This prepared stationary phase exhibited excellent abilities to separate polycyclic aromatic hydrocarbons (PAHs), polysiloxanes and phenols by HPLC. The chromatographic results show that both the C3 moiety and the amido-group in this phase contribute significantly to the HPLC separation process. The chromatographic behavior of the prepared phase and commercial C18 phases was also compared in analyses of PAHs and phenols. Although the commercial C18 phases have been extensively used, both the unique selectivity and the highly reproducible synthesis of our prepared phase make it an excellent complement to ordinary C18 phases.