Phenyl HPLC Columns

Ultra-low Bleed Phenyl Phase with Enhanced Phenyl Selectivity

Phenyl-based reversed-phases were one of the first alternatives to C18 selectivity. Our Ascentis Phenyl has been improved to offer exceptional phase stability and enhanced phenyl retention. Ascentis Phenyl offers versatility by also operating in the HILIC mode.


  • Low-bleed for MS or UV gradient applications due to the use of trifunctional bonding reagent
  • Outstanding phenyl selectivity due to high phase loading and short butyl spacer
  • 100% aqueous-compatible for highly-polar compounds

Structure of Ascentis Phenyl

USP Code: L11
Bonded Phase Description: Phenyl ring with short
butyl spacer
Endcapped: Yes
Particle composition: Type B silica gel
Particle Purity: <5 ppm metals
Particle Shape: Spherical
Particle Size: 3, 5 and 10 µm
Pore Size: 100 Å
Surface Area: 450 m2/g
Carbon Load: 19.5 %
pH Range (recommended): 2 to 8
Extended pH range*: 1.5 to 10

Key Applications

Small, water soluble molecules and peptides, π-acceptors, nitroaromatics, polar compounds, dipoles, heterocyclics, HILIC mode

Ordering Information for Ascentis Phenyl HPLC columns


Phenyl phases are π-basic (electron donating) and are similar in overall retention to alkyl and EPG phases for easy column screening. The alternate selectivity of phenyl phases is often explained by the π-π interactions available through the phenyl ring. Compounds that appear to exhibit differential selectivity on the phenyl phase include:

  • hydrophobic bases (TCAs, tetracyclines)
  • moderate bases (anesthetics and narcotic analgesics)
  • benzodiazepines
  • some acidic compounds such as ACE inhibitors and quinoline antibiotics
  • nucleosides (e.g. cytidine)
  • nitro, azide and sulfonyl compounds


  • Methanol can be a more selective mobile phase component than acetonitrile.
  • Activate HILIC mode by using highly-organic (>90%) mobile phases.

* Under certain conditions, the Ascentis family can be operated in the extended pH range. For more details, see “Acid/Base Stability of Silica Based on C8, C18, and Amide HPLC Columns” (T406018 - 530Kb pdf)