Chromatographic Gels
-Spherical Shape

ZEOsphere ultra-high-purity silica gels are designed to meet current and future demands in high-pressure liquid chromatography (HPLC), supercritical fluid chromatography (SFC) and continuous chromatography applications from analytical to process scale. Unique qualities of this high-performance spherical silica are:

  • High surface area
  • Mechanical strength
  • Chemical purity and stability
  • Optimized surface properties
  • Well-defined pore structure

Strict quality controls from raw material to finished product ensure excellent batch reproducibility and tightly controlled specifications. All products are available in various pore and particle sizes and are manufactured according to the ISO-9001 quality standard.

ZEOsphere HPLC silica consists of perfectly spherical, rigorous porous particles produced in various pore and particle sizes; custom tailored products are possible. The narrow particle size distribution ensures high performance, low-pressure drop and the best overall efficiency. It is manufactured using the well-known sol-gel technique, which gives optimized chemical and mechanical stability, pore structure and phase reproducibility. ZEOsphere silicas are available in different quantities with a wide variety of packing sizes to meet individual applications and economic requirements.

For more information on the ZEOsphere product portfolio, please visit our product catalog site at

zechem plant

Custom Solutions

Your one-stop shop for your process-scale chromatography needs.

ZEOprep, ZEObeads and ZEOsphere excel in their efficiency to create the best filtration, separation and purification solutions for a large variety of compounds and/or industries.

Classical Normal Phase – Bare (Unbonded) Silica

Normal phase HPLC applications suitable for separations of polar and basic organic compounds, such as vitamins and steroids, as well as pharmaceuticals. The rigid structure of the silica surface allows it to discern between molecules with different footprints that may have the same hydrophobicity. Isomers and related substances can be separated on unbonded silica under normal phase conditions.

Classical Normal Phase – CN

Normal-phase and reversed-phase modes suitable for separations of polar and basic organic compounds, such as vitamins and steroids, as well as pharmaceuticals. ZEOsphere’s cyano phase shows the retention behavior of normal-phase chromatography when used with low-polarity mobile phases such as hexane. Because the cyano stationary phase surface is less polar than bare silica gel, the retention times of analytes are generally shorter than with bare silica gel. Cyano is therefore appropriate for samples having too strong retention when analyzed using bare silica gel.

Cyano columns have alternative selectivity and equilibrate more quickly, offering greater suitability for normal-phase gradient separations compared to unbonded silica columns.

Classical Normal Phase – Diol

Suitable for separations of polar and basic organic compounds, such as vitamins and steroids, as well as pharmaceuticals.

Classical Normal Phase – NH2

Based on ultra-pure silica gel and suitable for separations of polar and basic organic compounds, such as vitamins and steroids, as well as pharmaceuticals. In normal-phase applications, the ZEOsphere amino (NH2) phases offer alternative selectivity to silica. They are particularly useful for the retention and separation of carbohydrates. The separation mechanism is based on hydrophilic and ionic interactions. NH2 is the most flexible in the normal phase family and can be used in three modes: normal phase, reversed phase and ion-chromatography mode (weak anion exchanger). In reversed-phase mode, it is primarily used for the analysis of carbohydrates.

Classical Reversed Phase – C18

100 angstrom, 120 angstrom and 200 angstrom ultra-high pure silica derivatized with C18 and endcapped. C18 is most preferred because it offers an excellent range of hydrophobic separation power along with high surface area coverage. C18 is most retentive for a wide range of acidic, basic and chelating compounds.

Classical Reversed Phase – C4

300 angstrom ultra-pure silica derivatized with C4 and endcapped. C4 has an excellent surface area and is available in multiple particle sizes. Its phases are specially designed for the separation of biological macromolecules which are too large or too hydrophobic for separations based on phases with smaller pores or longer alkyl chain bonded phases. C4 provides high efficiency and excellent peak shape and recovery.

Classical Reversed Phase – C8

100 angstrom, 120 angstrom, and 300 angstrom ultra-pure silica derivatized with C8 and endcapping offers an extensive range of hydrophobic separation power with high surface area coverage, in case less retention is required compared to a C18. Compounds elute faster, resulting in less time-consuming separations. The unique chemistry of bonded C8 ligands on ZEOsphere C8 phases provides exceptional performance for a variety of analytical and preparative applications.

Classical Reversed Phase – CN

100 Ångstrom ultra-pure silica with a high surface area and modified with cyano. Due to the CN group, it shows some polar functionality and some nonpolar functionality due to the propyl group. Thus, the column has intermediate polarity and is suitable for use in both the normal-phase and the reversed-phase modes. In the reversed phase mode, the column is less retentive than a C8 column. This makes the column ideal for situations where there is too much retention using a C8 column. Additionally, the column may be useful when there is a need to pull polar compounds away from nonpolar compounds. Common applications based on Cyano phases include the separation of flavonoids as well as analytes with a wide range of hydrophobicity.

  • In the reversed phase, the column is less retentive than a C8 column and behaves similarly in polarity compared to a C4 column for the retention of neutral compounds. This makes the column perfect for separations where there is too much retention using a C8 column.
  • In the normal-phase mode, the cyano column is in a less active polar phase than silica, which gives the user more flexibility in separation development.

Classical Reversed Phase – Phenyl and Derivatives

100 angstrom and 120 angstrom ultra-pure silica with a high surface area modified with phenyl, phenyl-butyl or phenyl-hexyl. ZEOsphere phenyl phases as reversed phase or in hydrophilic interaction liquid chromatography (HILIC) mode show alternative selectivity to C18 and C8 columns. The phenyl group provides the stationary phase with a moderate degree of hydrophobicity, making it ideal for the separation of analyte mixtures with different polarity and aromaticity. Key applications include small water-soluble molecules and peptides, π-acceptors, nitroaromatics, polar compounds, dipoles, heterocycles and HILIC mode.

Also available: phenyl-hexyl and phenyl-butyl.

  • Phenyl-hexyl offers unique selectivity for the separation of compounds that are difficult to resolve using traditional phenyl phases. Phenyl-hexyl is effective for resolving aromatic hydrocarbons such as in peptides, tricyclic antipsychotics such as benzodiazepines, and explosives. Like C18, phenyl-hexyl is ideal for a wide range of applications, including the resolution of moderate hydrophobic compounds.
  • Phenyl-butyl is ideal for the separation of isomers or structural analogs and is an alternative for standard phenyl for analytes with aromatic rings or long conjugated systems that tend to have strong retention.