(U)HPLC of Small Molecules
Widest range of HPLC and UHPLC columns for all separation modes and applications
Separation Mode
Reversed Phase, HILIC, Normale Phase
Safe Investment
Robust and reliable columns for attractive price
Simplicity
Easy purchase via our online store with fast delivery
Application
All-rounder for research or highly specialised for high-throughput analysis? We have the best column for your requirements.
Flexibility
Wide selection of column and particle sizes, for (U)HPLC applications up to 1000 bar
KNAUER (U)HPLC Columns
KNAUER offers the perfect column for any small molecule separation. No matter which separation mode, molecule and the mobile phase, we offer a suitable (U)HPLC stationary phase. Choose from a wide range of modifications, particle sizes and column dimensions to suit your application.
To elongate the lifetime of your column, you can choose to use a suitable precolumn.
Please let us know how we can help.
Modifications
Find the perfect stationary phase for your application
Classical and hydrophilic/aqueous C8 columns for HPLC and UHPLC (USP L7)
C8 is a silica gel based stationary phase in reversed phase mode with alternative selectivity compared to C18 phases.
Compared to C18 phases, these columns show less retention due to the lower hydrophobicity.
These phases are ideal for the analysis of:
- Water soluble vitamins
- Steroids
- Catecholamines
- Sedatives
Hydrophilic C8A phase offers an alternative, more polar selectivity. It is suited for highly polar reversed phase applications with up to 100 % aqueous mobile phases.
Classical Reversed Phase columns for HPLC and UHPLC (USP L1)
Most often used stationary phase in reversed phase mode. Silica gel based columns with C18 modification are available with or without endcapping. Classically endcapped phases are slightly more hydrophobic and unpolar than the not endcapped phases.
C18 columns are ideally used for acidic, basic and neutral analytes in reversed phase mode, e.g.:
- Sulphonamides
- Anabolic steroids
- Anti-psychotics
- Beta blocker
- Sudan dyes
- Phenols
- Preservatives
C18A columns for polar reversed phase applications with 100 % aqueous mobile phase (USP L1)
C18 stationary phase for the analysis of more polar and hydrophilic compounds in reversed phase mode (USP L1). Silica gel based columns with C18 modification with hydrophilic endcapping. Because of their modification, C18A phases can be operated under 100 % aqueous conditions without destroying the stationary phase, what is not recommended for classical C18 phases caused by their hydrophobicity.
These phases are ideal for the analysis of:
- Water soluble vitamins
- Organic acids
- Proteins and peptides
Hydrophobic / pH stable C18H Columns for more unpolar analytes in Reversed Phase (USP L1)
C18H stationary phase with a special, high efficiency or polymeric unpolar endcapping style. Because of the high carbon content and the protection of the Silica gel these materials are also suited for the use of mobile phase in an extended pH range from typically pH 1–12.
While a high endcapped C18H phase is characterized mostly by the high carbon content. A polymeric endcapped phase also provides an increased steric selectivity.
C18P columns with trifunctional modifications (USP L1): Hydrophobic and stearic interactions
KNAUER´s most unpolar C18P phase with excellent shape selectivity. It features polymeric, high efficiency endcapping of 99 % and 20 % carbon content, exceptional pH stability in the range of 1–12, and outstanding mechanical and chemical stability.
C4 columns for Reversed Phase in HPLC and UHPLC (USP L26)
C4 stationary phases (USP L26) are often used in reversed phase mode for different application areas. They are suitable for:
- Hydrophobic Interaction Chromatography (HIC mode)
- Analysis of biomolecules like proteins and peptides
Cyano or CN for Normal Phase and Reversed Phase (USP L10)
CN is one of the most versatile stationary phases that can be used in reversed phase mode as well as in normal phase mode.
The cyano modification supports the
π-π interaction as well as polar and hydrophobic interactions with low polarity solvents. These phases are preferred for compounds with double bonds and aromatic groups. Cyano bonded phases show unique selectivity for polar compounds and are more suitable than bare silica for normal phase (NP) gradient separations. The cyano functional group is a strong dipole that can interact with other dipoles or induce dipoles on solutes. These phases also exhibit moderate hydrophobicity due to the alkyl linker.
Due to the quick equilibration time of the CN bonded phase, it is the best choice for gradient elution in normal phase mode. CN phases can be used as a less polar alternative to Si phases.
The material is typically preferred for:
- Compounds with double bonds
- Cyclic antidepressants
DNPH columns for polar reversed phase applications with 100 % aqueous mobile phase (USP L1)
C18 stationary phase for the analysis of more polar and hydrophilic compounds in reversed phase mode (USP L1). Silica gel based columns with C18 modification with special endcapping, designed for DNPH analysis. Because of their modification, DNPH phases can be operated under 100 % aqueous conditions without destroying the stationary phase, what is not recommended for classical C18 phases caused by their hydrophobicity.
These phases are ideal for the analysis of:
- DNPH-derivates of aldehydes and ketones
Diol columns for Normal Phase in HPLC and UHPLC (USP L20)
Diol packing material can be universally used in different polar modes (NP, RP and HILIC). Diol bonded phases are a versatile alternative to unbonded silica for normal-phase separations with shorter equilibration times.
The hydroxyl groups provide good selectivity without excessive retention, caused by the weaker H-bonding of the diol layer than of silanols. Some diol bonded phases have been developed specifically for applications in the HILIC mode.
Diol packing material can be universally used in different polar modes (NP, RP and HILIC). Diol bonded phases are a versatile alternative to unbonded silica for normal phase separations with shorter equilibration times.
The hydroxyl groups provide good selectivity without excessive retention, caused by the weaker H-bonding of the diol layer than of silanols. Some diol bonded phases have been developed specifically for applications in the HILIC mode.
Diol columns for Normal Phase in HPLC and UHPLC (USP L20)
Phenyl stationary phases (USP L11) in reversed phase mode with alternative selectivity for
- Aromatic and moderately π-π interaction polar analytes
- Mixtures with varying polarity and aromaticity
The polarity is similar to C8 modification but with different selectivity for polar aromatics, polycyclic aromatic hydrocarbons, fatty acids etc.
Phenyl phases with a classical slightly hydrophobic endcapping or without endcapping.
Phenyl columns for Reversed Phase in HPLC and UHPLC
(USP L11)
Based on ultra-pure Silica gel, zwitterionic HILIC phases are ideal for the analysis of polar and ionizable compounds. Stronger interaction of more polar compounds with stationary aqueous layer.
Faster elution of nonpolar compounds is possible due to minor hydrophobic interactions. Retention increases with the charge of the analyte.
Recommended for the analysis of hydrophilic compounds like:
- Polar organic acids and bases
- Natural polar compounds
- Nucleosides
- Oligonucleotides
- Amino acids
- Peptides
- Water soluble vitamins
Zwitterionic and polar columns for HILIC applications
Amino columns for Normal Phase and for HILIC applications (USP L8)
Amino (NH2) bonded silica gel phases can be used in the normal phase (NP) and HILIC mode, but also for reversed phase (RP) mode. They show alternative normal phase selectivity to unbonded silica, especially for aromatics. Furthermore, the selectivity is influenced by hydrogen bond interactions with the analyte. Amino columns can also be used in the HILIC mode for carbohydrate analysis and for other polar compounds. Their weak anion-exchange properties can be used in the analysis of anions and organic acids.
The amino group is bonded to the silica support via a propyl linker.
Si columns for Normal Phase and HILIC applications (USP L3)
Unmodified Silica gel materials were the first ones used for chromatography. This is the reason the mode is called "normal phase" (NP). They are still used in HPLC, although reversed phase (RP) is by far the most often used HPLC mode today.
A wide range of porous Si materials are available, characterized by:
- Surface area
- Pore size
- Particle size
- Purity
- Metal content
Si columns for Normal Phase and HILIC applications (USP L3)
Unmodified Silica gel materials were the first ones used for chromatography. This is the reason the mode is called "Normal phase" (NP). They are still used in HPLC, although Reversed Phase (NP) is by far the most often used HPLC mode today.
