Performance Characteristics of the Agilent 1260 Infinity II Online Sample Manager

Significance of the Topic

The ability to monitor chemical and biological reactions in real time is crucial for process control in pharmaceutical and biopharmaceutical manufacturing. Automated online sampling and analysis reduce manual intervention, improve data reliability, and accelerate decision making to optimize yield and minimize impurities.

Aims and Study Overview

This technical overview evaluates the performance characteristics of the Agilent 1260 Infinity II Online Sample Manager. Key objectives include assessing precision in peak area and retention time, injection linearity over a broad volume range, and carryover under different sampling scenarios. Both classic flow-through and novel feed injection modes are compared using standard analytes.

Methodology and Used Instrumentation

The study employed inline sampling directly from a reactor interface and at-line injections from vials. Samples of caffeine and chlorhexidine were used to challenge system precision and carryover. Two injection modes were tested:

• Flow-through injection
• Agilent Feed Injection with controlled merge of sample and analytical flow

Major hardware components:

• Agilent 1260 Infinity II Online Sample Manager with external valve and OpenLab CDS control
• Agilent 1290 Infinity II High-Speed Pump
• Agilent 1290 Infinity II Multicolumn Thermostat
• Agilent 1290 Infinity II Diode Array Detector
• C18 UHPLC columns (RRHD 1.8 µm and 3.5 µm) and Pursuit XRs C18
• Software: OpenLab CDS 2.6 and Online LC Monitoring Software

Main Results and Discussion

• Peak area precision (RSD) declined with increasing volume; RSD values fell below 0.15% for injections ≥ 5 µL in both modes and sample sources.
• Injection linearity was excellent across 0.1–40 µL (R² > 0.9999), confirming reliable quantitation from sub-microliter to tens of microliter injections.
• Highly viscous samples (10 cP glycerin matrix) yielded area RSDs comparable to standard solutions, demonstrating robust handling of challenging matrices.
• Retention time precision for isocratic standards was < 0.03% RSD even under varying feed speeds, indicating stable flow control in feed injection mode.
• Carryover of a sticky analyte (chlorhexidine) remained below 30 ppm in vial-to-vial, vial-to-reactor, and reactor-to-vial sequences for both injection modes.

Benefits and Practical Applications

The Online Sample Manager enables near real-time reaction monitoring by automating dilution, quenching, and injection steps. It supports high-throughput screening, process development, and quality control, reducing manual workload and improving sample integrity.

Future Trends and Opportunities

Integration of advanced analytics (e.g., high-resolution mass spectrometry), machine learning for predictive process control, and expansion to multi-parameter inline sensors will further enhance reaction monitoring. Miniaturization and higher multiplexing capacity may enable broader adoption in continuous manufacturing.

Conclusion

The Agilent 1260 Infinity II Online Sample Manager delivers high precision, linearity, and low carryover across a wide injection volume range, even for viscous samples. Its dual injection modes and seamless reactor interface make it a powerful tool for automated reaction monitoring and process optimization.

Reference

• Reactor Sample Dilution and Mixing Performance of the Agilent 1260 Infinity II Online Sample Manager. Agilent Technologies Technical Overview, 5994-3679EN, 2021.
• Online Reaction Monitoring by the Agilent InfinityLab Online LC Solutions. Agilent Technologies Application Note, 5994-3528EN, 2021.