Unique Retention and Selectivity Enables Better Separations
Discovery® HS F5 Exhibits "U-Shape" Retention Profile
Under certain mobile phase conditions and with certain analytes, certain polar phases, like Discovery®
HS F5, can exhibit both reversed-phase and normal-phase behavior. At low percent organic, retention decreases with increasing percent organic following reversed-phase behavior. However, at higher percent organic, retention increases with increasing percent organic following normal-phase behavior. The result is a "U-shape" retention profile for these compounds. If your compounds exhibit this U-shape profile, use it to your advantage to:
- Improve LC-MS detection by using higher % organic mobile phase
- Use mobile phase concentration to alter selectivity at high % organic
HS F5 bonded fluoro (pentafluorophenyl) columns provide separations that are different from C18 columns. Unique selectivity plus the ability to transfer a C18 method make this an ideal complimentary reversed-phase for screening.
Small, water soluble molecules and peptides, polar compounds, basic compounds, positional isomers
- Compared to a phenyl phase: Although aromatic in nature, the pentafluorophenylpropyl (F5) phase does not resemble a phenyl phase in retention or selectivity. The F5 is a strong Lewis acid due to the electron withdrawing effects of five fluorine groups; the F5 ring is electron deficient whereas the phenyl ring is electron rich.