The Dual LC Concept for Productivity Increase in Various Applications and Industries

Importance of the Topic

High-throughput liquid chromatography is essential in pharmaceutical, biotechnology and food & beverage laboratories where hundreds of (U)HPLC analyses are performed daily. The Dual LC concept addresses the need for increased productivity and efficient use of bench space by integrating two independent flow paths into a single instrument.

Study Objectives and Overview

This work presents four case studies demonstrating how a Dual LC system can be used to:

• Double throughput by running identical methods in parallel
• Perform independent separations of compounds with very different properties
• Combine assay and impurity analyses in a single run
• Accelerate method development by scouting different chromatographic modes simultaneously

Methodology and Instrumentation

The Vanquish Flex Duo Dual LC system comprises:

• Two independent pumps and injection valves in a single housing
• One or two column compartments allowing simultaneous use of different columns
• Flexible detection options (UV, optical, non-optical) on each flow path

Two typical configurations were used:

• Setup 1: One column compartment with two columns, two pumps, two injection loops
• Setup 2: Two column compartments with independent solvent selection valves for advanced method scouting

Key Results and Discussion

Application 1: Stability-indicating assay of ezetimibe and simvastatin was performed in parallel on both flow paths, doubling sample throughput without loss of resolution or precision.

Application 2: Simultaneous assay and impurity testing of esomeprazole magnesium according to USP monograph, demonstrating consistent retention times and peak areas across both analyses.

Application 3: Independent separation of water-soluble and fat-soluble vitamins in beverages and tablets using different columns and methods, highlighting the system’s versatility.

Application 4: Accelerated method development for mRNA and its post-transcriptional impurities by concurrently scouting ion-exchange and ion-pair reversed-phase conditions, significantly reducing development time.

Benefits and Practical Applications

The Dual LC approach offers:

• Up to two-fold increase in analytical throughput with existing methods
• Reduced instrument count and laboratory footprint
• Flexible workflows enabling simultaneous multi-mode separations
• Time savings during method development and validation

Future Trends and Potential Applications

Emerging opportunities include:

• Integration with automated sampling and data-analysis software
• AI-driven method scouting and predictive retention modeling
• Coupling dual flows to high-resolution mass spectrometry for enhanced characterization
• Extension to multidimensional LC workflows for complex sample matrices

Conclusion

The Dual LC concept embodied in the Vanquish Flex Duo system effectively doubles laboratory throughput and accelerates method development by allowing two completely independent chromatographic processes in one instrument. This approach enhances productivity, reduces equipment requirements, and supports diverse analytical needs across industries.

References

• [1] Thermo Fisher Scientific Application Note 72601: Doubling the throughput of long chromatographic methods by using a novel Dual LC workflow
• [2] Thermo Fisher Scientific Application Note 001064: Simultaneous analysis of drug substances according to USP assay and impurity methods
• [3] Thermo Fisher Scientific Application Note 72592: Simultaneous determination of water- and fat-soluble vitamins by using a novel Dual LC system
• [4] Thermo Fisher Scientific Application Note 000471: Simultaneous reversed-phase and anion-exchange method scouting with a dual system for mRNA impurity determination