Mixed-Mode SPE

Reverse-phase alone retains analytes only through hydrophobic interaction, which can co-elute more matrix interferences. Adding a cation-exchange mechanism gives a second, independent retention pathway specific to protonated basic drugs, allowing a cleaner separation from neutral and acidic matrix components during the wash steps.

The C denotes the cation-exchange mode, meaning the sorbent carries a negatively charged functional group that retains positively charged, protonated basic analytes at an appropriate pH, which is why these products are chosen specifically for basic rather than acidic drug classes.

Yes, but a different mixed-mode chemistry is used, an anion-exchange variant carrying a positively charged functional group to retain negatively charged acidic analytes, rather than the cation-exchange products designed for basic drugs.