USP L11 column: Phenyl
Phenyl groups bonded to porous silica of 1.5-10 um, or to a monolithic rod.
Mode: reversed-phase Typical pH range: about 2-8 (silica base)
Typical uses
- Aromatic and conjugated compounds (pi-pi selectivity)
- Alternative selectivity when C18 cannot resolve impurities
- Some antibiotic and steroid methods
Common sizes (length x internal diameter, particle size)
- 250 x 4.6 mm, 5 um
- 150 x 4.6 mm, 5 um
- 100 x 2.1 mm, 1.7-1.8 um
Phenyl, phenyl-hexyl and biphenyl products are all sold as L11 but behave differently.
Example columns sold as USP L11
From the makers' own USP code lists and product pages, checked October 2026. Examples only, not an endorsement. Columns with the same code can still differ in selectivity; if the monograph names a column in its notes, start with that one.
| Maker | Product family | Particle | pH range |
|---|---|---|---|
| Agilent | InfinityLab Poroshell 120 Phenyl-Hexyl | superficially porous silica | not stated in source |
| Waters | XSelect CSH Phenyl-Hexyl | fully porous CSH hybrid 2.5/3.5/5 um | not stated in source |
| Thermo Fisher Scientific | Hypersil GOLD Phenyl | fully porous silica 1.9/3/5 um | 2-8 |
| Phenomenex | Luna Phenyl-Hexyl | fully porous silica 3/5/10/15 um | 1.5-9 (gradient), 1.5-10 (isocratic) |
| Phenomenex | Kinetex Biphenyl | core-shell (SPP) silica, 1.7 um shown | not stated in source |
| Merck (Supelco) | Ascentis Express Phenyl-Hexyl | Fused-Core (SPP) silica | not stated in source |
| YMC | YMC-Triart Phenyl | fully porous organic/inorganic hybrid 1.9/3/5 um | 1-10 |
| Restek | Raptor Biphenyl | SPP (core-shell) silica 1.8/2.7/5 um | 2-8 |
| Avantor (ACE) | ACE Ph | fully porous silica 2/3/5/10 um | 2-8 |
| Welch Materials | Ultisil XB-Phenyl | fully porous silica | not stated in source |
9 makers listed, so a tender written by USP code stays open to competition.
Tender wording (brand-neutral)
HPLC column with USP L11 packing (Phenyl), 250 x 4.6 mm, 5 um (length x internal diameter, particle size); stainless-steel or equivalent hardware with standard fittings; recommended pH and temperature range to be stated by the bidder; each column supplied with its certificate of analysis and test chromatogram, batch/lot number and serial number; shelf life not less than 2 years from delivery; any make meeting the USP L11 designation and the stated dimensions is acceptable.
Size:
Changing length or particle size
You can keep the USP L11 packing and use a different length, particle size or diameter within the harmonized USP 621 limits. Check your columns with the calculator.
Related column types
L1 C18 (octadecyl silane) | L7 C8 (octyl silane) | L10 Cyano (CN, nitrile) | L13 C1 (trimethylsilane) | L21 PS-DVB polymer (rigid) | L26 C4 (butyl silane) | L29 Polybutadiene-coated alumina (RP) | L43 PFP (pentafluorophenyl) | L60 Polar-embedded alkyl amide, endcapped | L62 C30 | L67 Polymer C18 (vinyl alcohol copolymer) | L68 Alkyl amide, not endcapped
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