Dr. KnowThe US Pharmacopeia (USP) is a standard source for many pharmaceutical methods. The USP specifies columns by packing material rather than by manufacturer. In most categories several different types of columns are listed which differ in particle size, particle shape, and perhaps carbon load or surface area. In these cases, the USP column specifications are quite broad and several column types meet the basic specifications. For example, an L1 specification calls for octadecyl silane chemically bonded to porous silica or ceramic micro-particles, 1.5 to 10 µm in diameter, or a monolithic rod.
Many commercially available columns meet the basic specifications and may be different particle types, including totally porous, superficially porous and monoliths. However, not all C18 columns are alike, and only a limited number of the available C18 columns from any vendor will actually perform the desired separation. For increased efficiency and resolution, we recommend spherical particles, totally porous or superficially porous from 1.5 to 3.5 µm in diameter. The USP specifically gives you the flexibility to determine the best column for your needs.
USP Designations and Agilent Columns
| USP Designation | USP Packing Material | Column | Particle Size (µm) | Pore Size (Å) |
| L1 | Octadecyl silane chemically bonded to porous silica or ceramic micro-particles, 1.5 to 10 µm diameter, or a monolithic silica rod | MetaSil AQ C18 Microsorb 100-5 C18 OmniSpher C18 Polaris C18-A Polaris C18-Ether Poroshell 120 EC-C18 Poroshell 120 SB-C18 Poroshell 120 HPH-C18 Poroshell 300SB-C18 Poroshell 300Extend-C18 Pursuit C18 Pursuit XRs C18 SepTech ST60 10-C18 SepTech ST150 10-C18 ZORBAX Eclipse Plus C18 ZORBAX Eclipse XDB-C18 ZORBAX Extend-C18 ZORBAX 300Extend-C18 ZORBAX ODS ZORBAX ODS classic ZORBAX Rx-C18 ZORBAX SB-C18 ZORBAX 300SB-C18 |
5 3 3, 5 3, 5, 10 3, 5 1.9, 2.7, 4 1.9, 2.7, 4 1.9, 2.7, 4 5 5 3, 5, 10 3, 5, 10 10 10 1.8, 3.5, 5 1.8, 3.5, 5, 7 1.8, 3.5, 5, 7 3.5, 5 3.5, 5, 7 5 3.5, 5 1.8, 3.5, 5, 7 1.8, 3.5, 5, 7 |
100 120 100, 120 180 200 120 120 100 300 300 200 100 60 150 95 80 80 300 70 70 80 80 300 |
| L3 | Porous silica microparticles, 1.5 to 10 µm in diameter, or a monolithic silica rod | MetaSil AQ Si Microsorb 100-5 Si Polaris Si-A Poroshell 120 HILIC Pursuit XRs Si ZORBAX Rx-Sil ZORBAX SIL ZORBAX HILIC Plus |
5 5 3, 5, 10 1.9, 2.7, 4 3, 5, 10 3.5, 5 5 3.5 |
80, 120 100 180 120 100 80, 300 70 95 |
| L4 | Silica gel of controlled surface porosity bonded to a solid spherical core, 30 to 50 µm in diameter | Custom order | ||
| L7 | Octylsilane chemically bonded to totally porous silica particles, 1.5 to 10 µm in diameter, or a monolithic silica rod | Microsorb 100-5 C8 Polaris C8-A Polaris C8-Ether Poroshell 120 EC-C8 Poroshell 120 SB-C8 Poroshell 120 HPH-C8 Poroshell 300 SB-C8 Pursuit C8 Pursuit XRs C8 ZORBAX C8 ZORBAX Eclipse Plus C8 ZORBAX Eclipse XDB-C8 ZORBAX Rx-C8 ZORBAX SB-C8 ZORBAX Rx-C8 ZORBAX C8 ZORBAX 300SB-C8 |
5 3, 5, 10 3, 5 1.9, 2.7, 4 2.7 2.7, 4 5 3, 5, 10 3, 5, 10 5 1.8, 3.5, 5 1.8, 3.5, 5, 7 1.8, 3.5, 5, 7 1.8, 3.5, 5, 7 1.8, 3.5, 5, 7 5 1.8, 3.5, 5, 7 |
100 180 200 120 120 100 300 200 100 70 95 80 80 80 80 70 300 |
| L8 | An essentially monomolecular layer of aminopropylsilane chemically bonded to totally porous silica gel support, 3 to 10 µm in diameter | Microsorb 100-5 Amino Polaris NH2 ZORBAX NH2 |
5 3, 5 5 |
100 180 70 |
| L9 | Irregular or spherical, totally porous silica gel having a chemically bonded, strongly acidic cation-exchange coating, 3 to 10 µm in diameter | SynChropak SCX ZORBAX SCX ZORBAX 300 SCX |
6.5 5 spherical 5 |
300 300 300 |
| L10 | Nitrile groups chemically bonded to porous silica particles, 3 to 10 µm in diameter | Microsorb 100-5 Cyano ZORBAX CN ZORBAX Eclipse XDB-CN ZORBAX SB-CN ZORBAX 300SB-CN |
5 5 3.5, 5 3.5, 5 3.5, 5, 7 |
100 70 80 80 300 |
| L11 | Phenyl groups chemically bonded to porous silica particles, 1.5 to 10 µm in diameter | Microsorb 100-5 Phenyl Pursuit Diphenyl Pursuit XRs Diphenyl ZORBAX Eclipse XDB Phenyl ZORBAX Eclipse Plus Phenyl-Hexyl ZORBAX Phenyl ZORBAX SB-Phenyl |
5 1.8, 3.5, 5 |
100 95 |
| L13 | Trimethylsilane chemically bonded to porous silica particles, 3 to 10 µm in diameter | ZORBAX TMS | 5 | 70 |
| L14 | Silica gel having a chemically bonded, strongly basic quaternary ammonium anion-exchange coating, 5 to 10 µm in diameter | IonoSpher A SynChropak SAX ZORBAX SAX |
5 6.5 5 |
120 300 70 |
| L15 | Hexyl silane chemically bonded to totally porous silica particles, 3 to 10 µm | MetaSil C6 | ||
| L17 | Strong cation-exchange resin consisting of sulfonated cross-linked styrene-divinylbenzene copolymer in the hydrogen form, 7 to 11 µm in diameter | Hi-Plex H Bio SCX NP10 |
8 |
N/A N/A |
| L19 | Strong cation-exchange resin consisting of sulfonated cross-linked styrene-divinylbenzene copolymer in the calcium form, about 9 µm in diameter | Hi-Plex Ca Hi-Plex Ca (Duo) |
8 8 |
N/A N/A |
| L20 | Dihydroxy propane groups chemically bonded to porous silica particles, 5 to 10 µm in diameter | MonoChrom Diol ProSEC 300S |
3, 5 5 |
110 300 |
| L21 | A rigid, spherical styrene-divinylbenzene copolymer, 5 to 10 µm in diameter | PLgel PLRP-S |
5, 10 5, 8 |
50, 100, 500, 103, 104, 105, 106 100, 300, 1,000, 4,000 |
| L22 | A cation-exchange resin made of porous polystyrene gel with sulfonic acid groups, about 10 µm in size | Hi-Plex H | 8 | N/A |
| L25 | Packing having the capacity to separate compounds with a Mol Wt MW range from 1,000 to 5,000 Da (as determined by polyethylene oxide), applied to neutral, anionic and cationic water-soluble polymers | PL aquagel-OH 30 | 8 | N/A |
| L26 | Butyl silane chemically bonded to totally porous silica particles, 3 to 10 µm in diameter | Microsorb C4 | 3, 5, 8, 10 | 300 |
| L27 | Porous silica particles, 30 to 50 µm in diameter | Bondesil Si SampliQ Bulk Silica, 25 g |
40 | 500 |
| L34 | Strong cation-exchange resin consisting of sulfonated cross-linked styrene-divinylbenzene copolymer in the lead form, about 9 µm in diameter | Hi-Plex Pb | 8 | N/A |
| L35 | A zirconium-stabilizes spherical silica packing with a hydrophilic (diol-type) molecular monolayer bonded phase | ZORBAX GF-250 ZORBAX GF-450 |
4 6 |
150 300 |
| L43 | Pentafluorophenyl groups chemically bonded to silica particles by a propyl spacer, 5 to 10 µm in diameter | Poroshell 120 PFP Pursuit PFP |
1.9, 2.7, 4 3, 5 |
120 200 |
| L45 | Beta cyclodextrin bonded to porous silica particles, 5 to 10 μm in diameter | ChiraDex Chiral Poroshell 120 Chiral-CD |
5 2.7 |
120 |
| L50 | A strong cation-exchange resin made of porous silica with sulfopropyl groups, 5 to 10 µm in diameter | SynChropak SCX | 5 | 300 |
| L52 | A strong cation-exchange resin made of porous silica with sulfopropyl groups, 5 to 10 µm in diameter | IonoSpher C | 5 | 120 |
| L56 | Propyl silane chemically bonded to totally porous silica particles, 3 to 10 μm in diameter | Poroshell 300SB-C3 ZORBAX SB-C3 ZORBAX 300SB-C3 |
3.5, 5 3.5, 5 |
80 300 |
| L57 | A chiral-recognition protein, ovomucoid, chemically bonded to silica particles, about 5 µm in diameter, with a pore size of 120Å | ULTRON ES-OVM | 5 | 120 |
| L58 | Strong cation-exchange resin consisting of sulfonated cross-linked styrene-divinylbenzene copolymer in the sodium form, about 6 to 30 µm diameter | Hi-Plex Na Hi-Plex Na (Octo) |
10 8 |
N/A N/A |
| L59 | Packing having the capacity to separate proteins by molecular weight over the range of 5 to 7000 kDa. The packing is spherical 1.5 - 10 μm silica or hybrid packing with a hydrophilic coating. | AdvanceBio SEC Bio SEC-3 Bio SEC-5 |
1.9, 2.7 3 5 |
120, 130, 200, 300 300 300 |
| L60 | Spherical, porous silica gel, 10 µm or less in diameter, the surface of which has been covalently modified with alkyl amide groups and end capped | Bonus-RP Poroshell 120 Bonus-RP Polaris Amide-C18 |
1.8, 3.5, 5, 7 2.7 3, 5, 10 |
80 120 180 |
| L63 | Glycopeptide teicoplanin linked through multiple covalent bonds to a 100 Angstrom units spherical silica. | Chiral-T | 2.7 | 120 |
| L86* | A 5 μ m fused core particle with a highly polar ligand possessing 5 hydroxyl groups tethered to the silica gel outer layer | HILIC-OH5 | 2.7 | 120 |
| L88 | Glycopeptide vancomycin linked through multiple covalent bonds to 100 - 200 Angstroms spherical silica. | Chiral-V | 2.7 | 120 |
| L96* | Alkyl chain, reversed-phase bonded totally or superficially porous silica designed to retain hydrophilic and other polar compounds when using highly aqueous mobile phases, including 100% aqueous, 1.5 to 10 µm. | Poroshell 120 SB-Aq ZORBAX SB-Aq |
1.9, 2.7, 4 1.8, 3.5, 5 |
120 80 |
| L114 | Sulfobetaine graft-polymerized to totally or superficially porous silica, 1.5 to 10 µm in diameter, or a monolithic rod. Packing having densely bonded zwitterionic groups with 1:1 charge balance. | Poroshell 120 HILIC-Z | 2.7 | 100 |
N/A - not applicable
