Polar phase: Crossbond acid-deactivated Carbowax polyethylene glycol Dedicated columns for free (underivatized) acids, some inorganic acids Resistant to oxidative damage Equivalent to USP G25 and G35 phases Similar phases: Stabilwax-DA, HP-FFAP, DB-FFAP, VF-DA, CP-Wax 58 CB, CP-FFAP CB, Nukol, BP-21, ZB-FFAP, AT-AquaWax-DA, AT-1000, EC-1000