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AMT HALO Phase Overview and HALO 2.7um

The HALO 2.7um materials from Advanced Materials Technology are the original phases manufactured using Fused-Core particle technology. These particles comprise a 1.7um solid core and a 0.5um porous outer shell. HALO columns provide the efficiency and separation speed of sub 2um particles but at approximately half the back pressure for the same column length. This lower pressure means that HALO columns can be used with conventional HPLC and LC-MS systems, as well as with UHPLC systems.

Later developments in the HALO series include HALO-5 (4.6um particles) and HALO 2 (2um particles) phases and the HALO BioClass columns.

  • Silica-based Fused-Core particle technology
  • Use with conventional HPLC or UHPLC systems
  • Wide range of bonded phases
  • Highly robust columns
  • Stable to 9000 psi (600 bar)

HALO C18 and C8 show excellent performance for a broad range of analyte polarities. Separations are due primarily to hydrophobic interactions and differences in hydrophobicity between analytes.

HALO RP-Amide columns offer complementary selectivity to HALO C18 and C8 and are recommended for samples containing acidic and basic compounds that require high aqueous eluents. Separations are influenced by both hydrophobic and hydrogen bonding interactions. The low bleed characteristics make HALO RP-Amide well suited for LC-MS applications.

HALO Phenyl-Hexyl separates analytes via by a combination of hydrophobic and π-π interactions. It shows enhanced retention and selectivity for aromatic and unsaturated analytes, especially those containing electron withdrawing groups and halogens. Columns are compatible with 100% aqueous mobile phases.

HALO PFP is particularly well suited for the separation of halogenated compounds, nitro-aromatic compounds and polar bases, with separations being primarily influenced by hydrogen bonding and dipole-dipole interactions. It has low bleed and is ideal for LC-MS applications. The phase can also be used in HILIC mode with mobile phases containing >80% acetonitrile.

HALO Penta-HILIC is a unique bonded phase that is particularly well suited for the separation of highly polar compounds that are poorly retained under typical reversed-phase conditions. HALO Penta-HILIC uses proprietary bonding chemistry that includes five hydroxyl groups on the bonded ligands. The phase is not endcapped, in order to maintain the high polarity of the material surface. The high density and polarity of the bonded phase minimise ion-exchange effects with residual silanols, thereby improving peak shape.

HALO HILIC (Silica) can be used in both HILIC and normal-phase modes. It shows enhanced sensitivity and peak shape for LC-MS analyses of basic analytes.

HALO ES-CN provides strong dipole-dipole interactions with analytes and weak hydrophobic interactions. It is suitable for use in reversed-phase, HILIC and normal-phase modes. The Extra Stable (ES) bonding, with sterically protected ligands, increases stability, especially at low pH (1- 4).

HALO 2.7um Phase Specifications

HALO PhaseParticle size (um) Pore size (A) Surface area (m2/g) Carbon load (%)Endcapped pH RangeUSP code
C182.7901357.7Yes2 - 9
C82.7901355.4Yes2 - 9
1358.2Yes2 - 9
Phenyl-Hexyl2.7901357.1Yes2 - 9
PFP2.7901355.5Yes2 - 9
Penta-HILIC2.7901353.2No2 - 9
HILIC (Silica)2.790135-No1 - 8L3
ES-CN2.7901353.5Yes1 - 8L10


  • HALO Product Catalogue
  • Quick Tips for Converting Conventional Reversed-Phase HPLC Separations to Ultra-Fast Separations (Mac-Mod)

Further technical information:

AMT Hichrom catalogue pages



HALO BioClass

For other Advanced Materials Technology products

Contact our Technical Support team