Catalog Number - 40008-10P

The 40008‑10P Cogent Bidentate C8™ HPLC Column is an analytical reversed‑phase column designed for methods where short (50 mm) columns do not provide sufficient resolution, but full long‑format columns are unnecessary. Built on Cogent TYPE‑C™ silica hydride technology, this column delivers excellent selectivity, faster equilibration, and extremely robust column lifetime compared with conventional silica‑based C8 columns.

The stationary phase consists of an aliphatic C8 hydrocarbon chain bonded via two direct silicon–carbon bonds (bidentate attachment) to a silica hydride surface. This non‑traditional chemistry produces a phase that is more hydrophobic than standard C8 columns, yet less hydrophobic than Bidentate C18™, making it ideal when C18 retention is excessive but stronger retention than conventional C8 is required. Unlike typical C8 phases, this column can also retain select hydrophilic compounds if desired.

The 100 mm column length increases plate count and separation efficiency compared to 50 mm formats, improving resolution of closely eluting compounds while maintaining reasonable run times. The column is also stable at very low pH (below pH 2) with no damage, significantly expanding method‑development flexibility.

Why Choose the 4.6 × 100 mm Bidentate C8™ Format

This column size is commonly selected when:

• 50 mm columns provide insufficient resolution

• C18 columns are overly retentive or slow

• Additional separation of closely eluting analytes is required

• Standard analytical flow rates and system hardware are preferred

The 100 mm length provides a practical balance between resolution and run time, while TYPE‑C™ silica hydride chemistry ensures fast equilibration and long column life.

Key Features

Cogent TYPE‑C™ Silica Hydride Technology

• Non‑traditional reversed‑phase surface chemistry

• Reduced silanol activity and secondary interactions

• Faster equilibration than conventional silica‑based C8 columns

• Extremely robust and reproducible column performance

Bidentate C8™ Bonding

• Two‑point attachment via direct Si–C bonds

• Balanced hydrophobic retention

• Alternative selectivity when C18 is overly retentive

Resolution‑Focused Analytical Geometry

• 4.6 mm ID × 100 mm length

• Higher resolving power than 50 mm formats

• Compatible with standard analytical flow rates

Broad Method Compatibility

• Stable at very low pH (below 2)

• Compatible with aqueous‑rich mobile phases

• Suitable for aggressive and unconventional analytical methods

Typical Applications

• Analytical HPLC requiring increased resolution

• Situations where C18 retention is excessive

• Alternative reversed‑phase selectivity

• Method development and optimization

• Low‑pH and aqueous‑rich mobile‑phase methods