Catalog Number - 85518-25P

The 85518‑25P Cogent RP C18 ABX™ HPLC Column is engineered for maximum‑separation analytical workflows, delivering rugged, reproducible performance across extreme mobile phase conditions (pH 2–12).

Built with a bulky, specially end‑capped C18 phase bonded to high‑purity silica, this column minimizes secondary interactions and improves peak shape for acidic, basic, hydrophobic, and neutral analytes, including compounds with very high or very low pKa values.

✅ Ideal as a USP L1 alternate for demanding acid/base methods ✅ One of the most powerful ABX columns for high‑purity analytical separations

250 mm Length – Maximum Separation & Highest Purity

• Highest resolving power in the 5 µm ABX analytical column range

• Maximizes peak capacity for highly complex mixtures

• Ideal for closely related compounds and trace impurity resolution

• Provides extended retention and superior peak separation

• Preferred for final method validation and highest‑purity results

✅ Selected when shorter columns (50 / 100 / 150 mm) cannot achieve required resolution

4.6 mm ID – Standard Analytical Platform

• Compatible with standard HPLC systems

• Ideal for:

  • QC and regulated workflows

  • method development and validation

  • high‑purity analytical separations

Typical Flow Rate Range

• ~0.8–1.5 mL/min

✅ Provides robust, reproducible analytical performance

5 µm Particle – Maximum Durability & Method Transferability

• Provides:

  • Long column lifetime

  • Excellent robustness under routine use

  • Lower backpressure vs smaller particle sizes

✅ Ideal for:

• Validated analytical methods

• Method transfer between laboratories

• High sample loads and routine workflows

Wide pH Stability (pH 2–12) – Extreme Method Capability

• Designed for acidic and basic mobile phase conditions

• Suitable for:

  • Strong acids

  • Strong bases

• Maintains structural integrity in aggressive analytical environments

✅ Enables separations beyond standard C18 column limitations

Why Choose RP C18 ABX™ Columns (5 µm)

Extreme pH Ruggedness

• Stable across full pH range (2–12)

• Ideal for stability‑indicating and high‑stress method conditions

Maximum Reliability & Reproducibility

• Designed for consistent results across systems and labs

• Supports regulated and validated workflows

Maximum Separation Capability

• Designed for highest resolution analytical applications

• Ideal for complex mixtures and impurity profiling

✅ Top choice for high‑purity analytical workflows requiring maximum separation

Application Performance Advantages

• Suitable for:

  • Hydrophobic compounds

  • Neutral analytes

  • Long‑chain fatty acids

• Enables:

  • Improved separation of complex matrices

  • Higher resolution vs shorter column formats

✅ Ideal for final method validation and high‑purity analytical workflows

System & Sample Considerations

• Compatible with standard HPLC systems

• Suitable for routine and advanced analytical workflows

Recommended sample preparation:

• 👉 Use 0.2 µm syringe filters for proper sample preparation before injection

✅ Helps:

• Prevent column fouling

• Maintain maximum performance and long‑term reproducibility

Typical Applications

• HPLC analytical separations

• Acidic and basic compound analysis

• Pharmaceutical QC and validation

• Stability‑indicating methods

• Impurity profiling and complex mixture analysis

• High‑purity analytical workflows

Important Usage Notes

• Designed for standard analytical HPLC systems (4.6 mm ID)

• Suitable for extreme pH mobile phases (pH 2–12)

• Ideal for maximum separation and highest‑purity workflows

• Monitor system pressure relative to instrument limits