Performance Characteristics of the Agilent 1260 Infinity II LC System – an Entry System for Routine Analysis

Significance of the topic

Liquid chromatography remains a cornerstone of routine analysis in pharmaceuticals, environmental testing and quality control. The need for reliable, high-throughput systems with robust retention time and area precision underlies efficient laboratory workflows, consistent data quality and seamless method transfer between laboratories.

Objectives and overview

This whitepaper evaluates the performance characteristics of the Agilent 1260 Infinity II LC System, positioned as an entry-level platform for routine HPLC and UHPLC analysis. Key performance metrics are assessed, including pump and injector precision, detector linearity, carryover, and system suitability under isocratic, gradient and fast-gradient conditions.

Methodology and instrumentation

The study employed:

• Agilent 1260 Infinity II quaternary pump (G7111B) capable of up to 600 bar
• Vialsampler with integrated column compartment and sample cooler (G7129A/G7130A)
• Variable wavelength detector (G7114B) with 10 mm flow cell
• OpenLab CDS ChemStation software (Rev. 2.4)
• InfinityLab Poroshell 120 EC-C18 columns (4.6×100 mm and 3×50 mm, 2.7 µm)

Chemicals included LC-grade acetonitrile, methanol, formic acid, trifluoroacetic acid and ultrapure water. Performance was tested with standard mixes (reversed-phase test mix, diagnostic mix, system suitability standard and seven-analyte LC/MS mix) and caffeine/chlorhexidine solutions.

Main results and discussion

Pump performance delivered outstanding retention time precision: <0.09% RSD under isocratic conditions, <0.03% RSD for conventional gradients, and <0.11% RSD for fast two-minute gradients (n = 7). Injector linearity for caffeine over 0.5–16 µL showed area and height RSDs <0.8%. Area precision under isocratic conditions (1–5 µL) remained <1% and under gradients (1–20 µL) <0.25% for volumes >5 µL. Carryover tests for 1,000 ng chlorhexidine and 2,500 ng caffeine with a 3 s wash showed no detectable residual peaks. Detector linearity for caffeine 1.5–800 ng was maintained within a 5% response-factor range. The LC/MS seven-analyte standard exhibited RT RSDs ~0.03–0.04% and area RSDs <2%.

Benefits and practical applications

The Agilent 1260 Infinity II system offers:

• High retention time and area precision for consistent quantitation
• Strong injection volume linearity across a wide range
• Negligible carryover for trace-level analyses
• Compatibility with routine HPLC and low-throughput UHPLC workflows
• Easy method transfer and stepwise upgrades to protect existing investments

These attributes suit pharmaceuticals, food and beverage, environmental testing and QC laboratories seeking reliable entry-level LC performance.

Future trends and potential applications

Emerging opportunities include:

• Integration with higher-pressure UHPLC columns for faster separations
• Enhanced automation and sample-handling robotics
• Coupling with advanced mass spectrometry for multi-dimensional analysis
• Machine-learning–driven method optimization and predictive maintenance

Conclusion

The Agilent 1260 Infinity II LC System meets modern demands of routine chromatographic analysis with exceptional precision, linearity and zero carryover across varied conditions. Its modular design and upgrade paths allow laboratories to scale performance and maintain data quality while managing budgets.