The ACE C18-AR phase is a long-chain phenylalkyl phase, which adds phenyl (aryl) selectivity to C18-like retention.   C18-AR offers hydrophobic, p–p, and dipole-dipole interactions with analytes, and shows increased retention for analytes with electron-withdrawing groups.  It offers complementary selectivity to ACE C18, C18-PFP, C18-Amide, CN-ES, and SuperC18 phases, and is fully wettable with no organic modifier in the mobile phase in both isocratic and gradient modes.   C18-AR has been shown to be an extremely stable and ultra-low bleed phase for LC-MS workflows, and is available in HPLC and UHPLC configurations, including nano, capillary, analytical, and preparative dimensions.



  • Ideal column choice for method development when  C18 retention and alternate selectivity is needed
  • Complementary retention and selectivity to ACE C18, C18-PFP, C18-Amide, CN-ES and SuperC18 bonded phases
  • Useful for analytes that contain electron withdrawing moieties:  -NO2, -halides, -NR3+, -SO2,
    -CO2H, -SO3H, -CO2R, -CHO, etc.
  • Compatible with 100% aqueous mobile phases and provides increased retention for polar analytes
  • Stable using low and mid pH eluents (pH 2–8)
  • Ultra-low bleed for UV-VIS and LC/MS compatibility
High efficiency 2 μm, 3 μm, 5 μm and 10 μm particles for UHPLC, HPLC and preparative separations

Figure 1: ACE C18-AR can provide additional retention and selectivity in highly aqueous mobile phases for polar analytes

In this example, ACE CN-ES provides significantly more retention than the shorter chain cyanopropyl phase (ACE CN), and it offers comparable retention but different relative retention compared to the ACE C18 phase.

Figure 2: ACE C18-AR can deliver improved selectivity and resolution compared to C18 phases

Figure 3: Synthetic cannabinoids (SPICE compounds) in oral fluids are readily separated using ACE C18-AR and detected using LC-MS-MS


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