Dual-Reactor Sampling with Agilent InfinityLab Online LC Solutions

Significance of the Topic

The integration of automated sampling with online liquid chromatography (LC) enables precise, reproducible monitoring of reaction progress in real time. In pharmaceutical and biopharma process development, high temporal resolution sampling from multiple reactors supports rapid decision making, reduces manual workload, and ensures data consistency for quality control and kinetic studies.

Objectives and Study Overview

This study aimed to demonstrate the use of the Agilent 1290 Infinity Flexible Cube as an integrated sampling device for the Agilent InfinityLab Online LC platform. Key goals included automated alternation between two reaction vessels undergoing acetyl salicylic acid hydrolysis at pH 10.0 and pH 9.0, seamless control via OpenLab CDS and Online LC Monitoring Software, and real-time visualization of reaction kinetics.

Methodology and Instrumentation

The setup combined an Agilent 1290 Infinity Flexible Cube equipped with two stream-selection valves and a piston pump, an Agilent 1260 Infinity II Online Sample Manager, a high-speed pump, a multicolumn thermostat, and a diode array detector. Control was achieved through Agilent OpenLab CDS (v2.6+) and Online LC Monitoring Software (v1.1). Sampling from two 50 mL reactors containing acetyl salicylic acid in glycine buffer (pH 9.0 and pH 10.0) was scheduled every 30 minutes over 10 hours. Each cycle included sample draw, dilution in a deep-well plate, chromatographic analysis under isocratic conditions (35% ACN/FA, 1 mL/min, 45 °C), and flushing with up to three solvents to prevent carryover.

Main Results and Discussion

Trending plots of peak areas for acetyl salicylic acid and its hydrolysis product, salicylic acid, revealed rapid conversion at pH 10.0 with 50% conversion achieved after ~70 minutes. At pH 9.0, conversion remained below 50% after 10 hours, confirming slower kinetics. An isocratic separation yielded retention times of 0.259 minutes for acetyl salicylic acid and 0.310 minutes for salicylic acid, enabling high-throughput analysis.

Benefits and Practical Applications

• Fully automated, unattended sampling from multiple reactors reduces labor and manual error.
• Flexible Cube flushing and valve switching prevent cross-contamination between conditions.
• Real-time data acquisition and trending allow rapid process optimization and kinetic modeling.
• Compact, integrated workflow simplifies connectivity and control in regulated environments.

Future Trends and Potential Applications

Advancements may include integration with mass spectrometry detectors for enhanced analyte specificity, expanded multiplexing to four or more reactors, and machine-learning driven feedback control. Coupling real-time data streams with predictive models will further accelerate process development in pharmaceutical R&D and manufacturing.

Conclusion

The Agilent 1290 Infinity Flexible Cube, when combined with InfinityLab Online LC Solutions, provides a robust, flexible platform for dual-reactor sampling and real-time reaction monitoring. Seamless control via OpenLab CDS and Online LC Monitoring Software delivers high data quality, streamlined workflows, and valuable kinetic insights for research and quality assurance applications.

References

• Naegele, E.; Herschbach, H. Delivery of Reactants from a Batch Reactor Using the Agilent InfinityLab Online LC Solutions. Agilent Technologies Technical Overview 5994-5658EN (2023).
• Naegele, E.; Kutscher, D. Online Reaction Monitoring by the Agilent InfinityLab Online LC Solutions. Agilent Technologies Application Note 5994-3528EN (2021).