Prep HPLC Column, Bidentate C18, 4um, 100A. 21.2mm ID x 250mm Length. Cogent TYPE-C Brand. 1 EA.
Additional Info:
The 40018‑P21‑250 Cogent Bidentate C18™ Preparative HPLC Column is the longest, highest‑resolution preparative option in the Bidentate C18™ lineup. It is engineered for purification workflows that require maximum separation power, 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 employs an aliphatic C18 chain bonded via two direct silicon–carbon bonds (bidentate attachment) to a silica hydride surface. This non‑traditional chemistry creates a phase that is highly hydrophobic yet versatile, enabling strong and stable retention of hydrophobic molecules, metabolites, and amine‑containing analytes—including under aqueous‑dominant or low‑pH mobile‑phase conditions that commonly challenge conventional silica‑based prep C18 materials.
With a 21.2 mm internal diameter and an extended 250 mm length, this column provides the highest plate count available in a 21.2 mm preparative format, making it the preferred choice when closely eluting impurities or structurally related compounds must be fully resolved prior to fraction collection.
System Note: A specialized preparative HPLC system (high‑flow pump capacity, appropriate tubing/valving, injector, and fraction‑collection hardware) is required for columns of this size and length.
Why Choose the 21.2 × 250 mm Prep Bidentate C18™ Format
This configuration is typically selected when:
Maximum purification resolution is required
Shorter preparative columns (50–150 mm) do not provide adequate separation
High‑mass loads include closely related impurities or isomers
The highest possible fraction purity is required for downstream processing
The extended column length substantially increases interaction time and selectivity, while TYPE‑C™ silica hydride chemistry maintains fast equilibration and long service life despite aggressive preparative methods.
Key Features
Cogent TYPE‑C™ Silica Hydride Technology
Reduced silanol activity and secondary interactions
Faster equilibration than conventional prep C18 columns
Very robust lifetimes for repeated purification cycles
Bidentate C18™ Bonding
Two‑point attachment via direct Si–C bonds
Strong, stable hydrophobic retention
Particularly effective for hydrophobic and basic analytes
Preparative Geometry for Maximum Resolution
21.2 mm ID × 250 mm length
Highest plate count among 21.2 mm prep options
Enables tight fraction cut windows and superior purity
Broad Operating Window
Compatible with aqueous‑dominant mobile phases
Stable under low‑pH conditions
Tolerates aggressive purification methods
Typical Applications
Preparative purification requiring maximum separation
Isolation of closely related or structurally similar compounds
Hydrophobic molecule and metabolite purification
Amine‑containing analytes
Scale‑up from analytical or shorter preparative methods
Made‑to‑Order & Pricing Information
This is a custom, made‑to‑order item.
Orders cannot be canceled once placed
Custom items are non‑returnable