Zorbax Extend

Zorbax Extend-C18 Capillary/Microbore HPLC Columns from Agilent

Extend-C18 columns incorporate a unique patented bidentate silane, combined with a double-endcapping process that protects the silica from dissolution at high pH - up to pH 11.5. Columns are best applied for separations of compounds that are either basic and have little or no retention at low or intermediate pHs, more stable or more soluble at high pH, or basic and show poor peak shape at low or intermediate pH.

Available with a 80 Å pore size for small molecule applications and a 300 Å pore size for biochromatography applications.

Zorbax Extend


Zorbax Extend-C18

  • High efficiency and long life at high pH - up to pH 11.5
  • Unique bidentate bonding and double endcaping provides high pH stability
  • More efficiency and better peak shape than polymer-based columns
  • Improve retention, resolution and peak shape of basic compounds

Zorbax 300Extend-C18

  • Rugged, high and low pH separations of peptides, polypeptides, and small proteins from pH 2 - 11.5
  • Different selectivity possible at high and low pH
  • High efficiency and good recovery of hydrophobic peptides at high pH
  • Ideal for LC-MS with ammonium-hydroxide-modified mobile phase
  Pore Size Surface Area Temp Limits* pH Range** Endcapped Carbon Load USP Designation
ZORBAX Extend C18 80 Å 180 m2/g 60 ºC 2 - 11.5 Double 12.5% L1
ZORBAX 300 Extend C18 300 Å 45 m2/g 60 ºC 2 - 11.5 Double 4% L1

Specifications represent typical values only.
*Temperature limits are 60 °C up to pH 8, 40 °C from pH 8-11.5.
**Above pH 6 highest column stability for all silica based columns is obtained by reducing the operating temperature to 40 ºC or below and using lower buffer concentrations (0.01-0.02M) or organic buffers.