Prep HPLC Column, Bidentate C8, 4um, 100A. 21.2mm ID x 250mm Length. Cogent TYPE-C Brand. 1 EA.
Additional Info:
The 40008‑P21‑250 Cogent Bidentate C8™ Preparative HPLC Column is the longest and highest‑resolution preparative option in the Bidentate C8™ lineup, engineered for purification workflows that demand maximum separation, extended retention, and the highest achievable fraction purity. Built on Cogent TYPE‑C™ silica hydride technology, this column delivers excellent selectivity, fast equilibration, and very robust column lifetime under demanding preparative conditions.
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 creates a phase that is more hydrophobic than conventional C8 columns, yet less hydrophobic than Bidentate C18™, making it ideal for hydrophobic molecules, metabolites, and amine‑containing analytes when C18 is overly retentive and limits purification efficiency.
With a 21.2 mm internal diameter and extended 250 mm length, this column provides the highest plate count and resolving power in the 21.2 mm preparative series, enabling separation of closely eluting impurities, isomers, or structurally related compounds prior to fraction collection. The longer bed length increases interaction time, allowing tighter fraction cut windows and improved product purity.
System Note: A specialized preparative HPLC system (high‑flow pump capacity, properly sized injector, tubing/valving, and fraction‑collection hardware) is required for columns of this size and length.
Why Choose the 21.2 × 250 mm Prep Bidentate C8™ Format
This configuration is typically selected when:
Maximum preparative resolution is required
Shorter columns (50–150 mm) do not resolve critical components
Complex mixtures contain closely related compounds or isomers
C18 columns are too retentive or reduce throughput
Highest fraction purity is required before downstream processing
The extended column length significantly increases selectivity and separation capacity, while TYPE‑C™ silica hydride chemistry maintains fast equilibration and long service life.
Key Features
Cogent TYPE‑C™ Silica Hydride Technology
Non‑traditional reversed‑phase chemistry
Reduced silanol activity and improved peak shape
Faster equilibration than conventional preparative C8 columns
Very robust lifetime for repeated purification workflows
Bidentate C8™ Bonding
Two‑point attachment via direct Si–C bonds
Balanced hydrophobic retention
Ideal alternative when C18 is overly retentive
Preparative Geometry for Maximum Resolution
21.2 mm ID × 250 mm length
Highest plate count in the preparative series
Enables tight fraction cuts and high‑purity isolation
Broad Method Compatibility
Stable at very low pH (below 2)
Compatible with aqueous‑rich mobile phases
Suitable for aggressive purification methods
Typical Applications
Preparative purification requiring maximum resolution
Isolation of closely related or structurally similar compounds
Hydrophobic molecule purification
Metabolite and amine‑containing analyte separation
Scale‑up from analytical or shorter preparative methods
Complex mixture purification workflows
Made‑to‑Order & Pricing Information
This is a custom, made‑to‑order item.
Orders cannot be canceled once placed
Custom items are non‑returnable