HPLC Column, UDA (wcx) 2.o, 2.2um, 2.1mm ID x 50mm Length, 120A, High. Cogent TYPE-C Brand. 1 EA.
Dual‑Mode ANP and Weak Cation Exchange for LC‑MS
Reversed Phase (RP) or ANP | Weak Cation Exchange | TYPE‑C™ Silica Hydride
Cogent UDA™ HPLC columns are a highly specialized TYPE‑C™ silica hydride stationary phase designed to operate in aqueous normal phase (ANP) with the added capability of weak cation exchange (WCX) under appropriate mobile‑phase conditions. This unique chemistry allows analysts to access dual separation mechanisms within a single column.
UDA™ columns are especially well suited for LC‑MS applications, complex sample matrices, and method development where minimal desalting and high reproducibility are required.
Unique Undecanoic Acid (UDA) Chemistry on TYPE‑C™ Silica
Cogent UDA™ columns feature an 11‑carbon aliphatic linker bonded to a silica hydride surface, terminating in a carboxylic acid functional group (undecanoic acid). This structure provides a distinctive combination of:
Hydrophobic interaction from the long alkyl chain
Polar retention via ANP mechanisms
pH‑dependent weak cation exchange behavior
Because the ligand is bonded to a TYPE‑C™ silica hydride surface, the column benefits from the inherent stability, fast equilibration, and low water affinity characteristic of silica hydride phases.
Dual‑Mode Operation: ANP and Weak Cation Exchange
One of the most powerful features of Cogent UDA™ is its ability to function in two distinct separation modes, depending on mobile‑phase pH.
Aqueous Normal Phase (ANP) Mode
At lower pH values (below ~4.9), the carboxylic acid group is largely non‑ionized. In this state, the column behaves primarily as an ANP phase, retaining polar compounds without significant ion‑exchange interactions.
This mode is ideal for:
Polar and moderately polar analytes
LC‑MS workflows requiring low salt
Complex biological or chemical matrices
Weak Cation Exchange (WCX) Mode
As mobile‑phase pH increases, the carboxylic acid group becomes ionized:
~90% ionized above pH 5.9
~99% ionized at pH 6.9
In this state, the stationary phase carries a negative charge and can function as a weak cation exchanger, selectively retaining positively charged (basic) analytes.
✅ Recommendation: To take advantage of the cation‑exchange functionality, use a mobile phase at pH ~6 or higher, when method conditions allow.
Ideal for LC‑MS and Complex Matrices
Cogent UDA™ columns are a strong choice for LC‑MS due to their TYPE‑C™ silica hydride surface, which:
Minimizes water adsorption
Reduces the need for extensive desalting
Improves signal stability
Enables precise, reproducible gradient methods
These characteristics make UDA™ columns especially effective when working with complex biological or chemical samples, where traditional ion‑exchange columns may require extensive sample cleanup.
Key Features and Benefits
TYPE‑C™ silica hydride stationary phase
Undecanoic acid (UDA) ligand with C11 linker
Dual‑mode operation: ANP + weak cation exchange
pH‑dependent ionization for tunable selectivity
Excellent for LC‑MS workflows
Minimal desalting requirements
Fast equilibration and high reproducibility
Suitable for RP or ANP methods
Typical Applications
LC‑MS and LC‑MS/MS
Polar and basic compounds
Complex biological matrices
Method development requiring dual selectivity
Aqueous normal phase (ANP) separations
Weak cation exchange workflows with low salt
Additional Resources
Column Protection Recommendation
Important: MICROSOLV technical support strongly recommends using the Cogent Column Filter, which is included with each column, whenever possible. Column filters help protect against particulates, extend column lifetime, and maintain consistent chromatographic performance.
👉 Learn more about the Cogent Column Filter for HPLC column protection
