Chiral Analysis of Hydrophobic Amino Acids with Agilent InfinityLab Poroshell 120 Chiral-T Column

Importance of the Topic

Amino acids are fundamental building blocks in biology, pharmaceuticals, and industry. Their chirality influences biological activity, nutritional value, and analytical quality control. Fast and reliable separation of D- and L-enantiomers supports drug development, metabolic studies, and regulatory compliance, especially for underivatized hydrophobic amino acids.

Objectives and Study Overview

This work demonstrates the rapid chiral separation of four aliphatic amino acids (alanine, valine, leucine, isoleucine) using an Agilent InfinityLab Poroshell 120 Chiral-T column. The goal was to achieve baseline resolution of underivatized enantiomer pairs with a methanol/ammonium formate buffer system and detect them by evaporative light scattering detection.

Methodology

• Stationary phase: Agilent InfinityLab Poroshell 120 Chiral-T (2.1 × 100 mm, 2.7 μm)
• Mobile phase: 70:30 (v/v) methanol/25 mM ammonium formate buffer (pH 3.0)
• Flow rate: 0.21 mL/min; column temperature: 30 °C
• Injection: 1 μL; sample concentration: 2 mg/mL in water
• Detection: ELSD (evaporator 30 °C; nebulizer 30 °C; gas flow 1 SLM; 40 Hz)

Instrumentation Used

• Agilent 1290 Infinity II flexible pump
• Agilent 1290 Infinity II autosampler with ultralow dispersion components
• Agilent 1290 Infinity II multicolumn thermostat
• Agilent 1290 Infinity II evaporative light scattering detector
• Agilent OpenLab CDS software

Main Results and Discussion

Baseline separation of all four D/L enantiomer pairs was achieved in under four minutes. High resolution and selectivity values illustrate effective chiral recognition by the teicoplanin-based glycopeptide phase under reversed-phase conditions.

• Alanine: k1=0.82, k2=1.54, resolution (Rs)=4.52, selectivity=1.86
• Valine: k1=0.66, k2=1.13, Rs=3.32, selectivity=1.72
• Leucine: k1=0.68, k2=1.41, Rs=4.63, selectivity=2.07
• Isoleucine: k1=0.63, k2=1.30, Rs=4.41, selectivity=2.04

Benefits and Practical Applications

The method delivers rapid throughput, robust performance, and compatibility with mass spectrometry-friendly solvents. Its high efficiency and baseline resolution enable routine enantiomeric purity assessment in pharmaceutical, nutritional, and biochemical laboratories without derivatization steps.

Future Trends and Opportunities

Potential developments include coupling this chiral phase with mass spectrometers for enhanced sensitivity, extending the approach to other amino acids and small chiral molecules, and further reducing analysis time through ultra-high-pressure operation or alternative buffer systems.

Conclusion

The Agilent InfinityLab Poroshell 120 Chiral-T column provides a fast, high-resolution, and reliable method for separating underivatized hydrophobic amino acid enantiomers under reversed-phase conditions. Its compatibility with common solvents and ELSD detection makes it a versatile tool for analytical and quality control applications.

References

• Agilent Technologies, Application Note 5994-1366EN, September 2019.