This paper describes a unique Prep-rP-HPLC technique that uses a C-18/C-8 derivatized silica coated with a hydrophobic quaternary ammonium salt or quaternary phosphonium salt that acts as an ...

Figure 1: Schematic representation of the continuous FFE apparatus coupled off-line to RP-HPLC. Hydroxypropyl methyl cellulose (HPMC) stock solution, 2% (wt/vol; ∼86 K nominal molecular weight; ...