NEW Selectivity Luna Omega HILIC

Importance of the topic

The retention and selective separation of small, highly polar analytes remains a persistent challenge in liquid chromatography. HILIC stationary phases with tuned polar functionality enable improved retention and orthogonal selectivity compared with reversed-phase methods, supporting analysis of metabolomics targets, nucleobases, sugars and other polar compounds. The Luna Omega HILIC diol (OH) phase targets this need by combining a diol-bonded surface with thermally modified fully porous particles to deliver enhanced retention, robustness and extended column lifetime for routine and high-throughput applications.

Objectives and overview of the product example

The provided application note and product information demonstrate the selectivity and performance of the Luna Omega HILIC diol column for separating nucleobases. Key goals shown are to: improve retention and resolution of small polar analytes, demonstrate a rapid separation of nucleobases, and detail column characteristics and operating conditions to guide method development and ordering decisions.

Methodology and used instrumentation

The demonstration uses a Luna Omega 3 µm HILIC diol column (150 x 4.6 mm) under the following conditions and properties:

• Stationary phase: Diol-bonded HILIC (OH) providing multiple polar interaction mechanisms for enhanced selectivity.
• Particle size: 3 µm fully porous, thermally modified particles.
• Pore size: 100 Å.
• Surface area: ~260 m2/g; carbon load: ~5%.
• Column dimension: 150 x 4.6 mm (demonstration); other available sizes include mini-, mid-bore and analytical formats across common lengths and diameters.
• Mobile phase: 100 mM ammonium formate, pH 3.2 : acetonitrile (10:90 v/v) — high organic content typical for HILIC.
• Flow rate: 1.0 mL/min.
• Column temperature: 22 °C.
• Detection: UV at 260 nm (appropriate for nucleobases).
• pH operating range: approximately 2.0–7.0.
• Pressure limit: 1034 bar (15,000 psi), enabling high throughput and compatibility with UHPLC-capable systems.
• Part number for demonstrated column: 00F-4808-E0 (Luna Omega HILIC, 3 µm, 150 x 4.6 mm).

Main results and discussion

The example chromatogram separates five canonical nucleobases with a short total run time on the order of 9 minutes. The observed elution order reported is:

1. Thymine
2. Uracil
3. Adenine
4. Cytosine
5. Guanine

Key performance observations and implications:

• Retention and resolution: The diol-bonded HILIC surface increases retention for these small, polar bases via a combination of hydrogen bonding, polar partitioning and secondary interactions, producing baseline-capable separation within a short analysis time.
• Speed vs. selectivity: High organic mobile phase composition (acetonitrile ~90%) shortens analysis time while preserving HILIC retention; this balance suits high-throughput screening and routine QC workflows for polar analytes.
• Robustness: Thermally modified fully porous particles and moderate carbon load support consistent performance and extended column life under typical HILIC conditions.
• Compatibility: Operating pH window (2–7) and high pressure rating permit method flexibility while maintaining column integrity.

Benefits and practical applications of the method

The Luna Omega HILIC diol phase offers several practical advantages:

• Improved selectivity for small polar analytes (e.g., nucleobases, small metabolites, mono- and disaccharides) relative to many reversed-phase columns.
• Faster assays for polar targets due to strong retention at high organic fractions, enabling shorter cycle times for screening and QC.
• Robustness for routine use thanks to thermally modified particles and a pressure rating compatible with modern HPLC/UHPLC systems.
• Multiple available column formats and SecurityGuard cartridge options facilitate method transfer and protect analytical columns in high-throughput or complex-matrix applications.

Future trends and opportunities for use

HILIC phases with controlled polar chemistries will continue to expand in areas where polar analytes dominate. Expected developments and opportunities include:

• Integration with MS detection: Optimization of volatile buffers and additive strategies to pair HILIC selectivity with sensitive mass spectrometric detection for metabolomics and pharmaceutical impurity profiling.
• Miniaturization and UHPLC performance: Further adoption of sub-2 µm and superficially porous formats to shorten run times while maintaining resolution for complex polar mixtures.
• Method libraries and retention prediction: Accumulation of robust retention data for polar compounds will improve method transfer and retention-time prediction using machine learning models.
• Application growth in biopharma and environmental analytics where polar small molecules, degradation products and polar impurities require reliable separation.

Conclusion

The Luna Omega HILIC diol stationary phase provides enhanced retention and selectivity for small polar analytes through a diol-bonded surface on thermally stabilized fully porous particles. The supplied nucleobase example demonstrates rapid, well-resolved separations using a high-organic mobile phase and common buffer, illustrating the phase's suitability for routine polar analyte analysis, method development and high-throughput workflows. A broad range of column sizes and guard cartridge options support flexible deployment across research and QC laboratories.

Reference

• Phenomenex product and application information: Luna Omega HILIC (Diol, OH) — product literature and application data. Phenomenex, Inc., 2025. Part No. 00F-4808-E0.