CHIRALPAK QN-AX and CHIRALPAK QD-AX are enantioselective weak anion-exchange (AX) HPLC columns. The chiral selectors for CHIRALPAK QD-AX and CHIRALPAK QN-AX anion exchange phases are based on complementary quinine (QN) and quinidine (QD) derivative selectors bonded to high-efficiency 5-µm diameter spherical silica. The structure of these selectors is such that a tertiary amine is located in a three-dimensional cleft surrounded by additional hydrogen binding sites and a large aromatic group. This combination provides excellent separations of chiral acids. These columns can be used in reversed-phase (RP) mode or in polar organic mode (non-aqueous, polar organic solvents containing organic acids and bases as buffer constituents). In addition, the separation of chiral basic and neutral compounds may also be possible, but usually under normal-phase (NP) conditions.

Columns packed with the CHIRALPAK QD-AX and CHIRALPAK QN-AX selectors are available in 2.1-, 4.6- and 20-mm internal diameter to allow separations on analytical and semi-preparative scales.