Performance Characteristics of the Agilent 1290 Infinity II Multisampler

Significance of the Topic

The precise and reliable introduction of liquid samples is fundamental to high-performance liquid chromatography workflows across pharmaceutical, environmental and quality-control laboratories. The Agilent 1290 Infinity II Multisampler delivers robust automation, broad volume range and minimal carryover, addressing the growing demand for high-throughput, reproducible results under diverse chromatographic conditions.

Objectives and Study Overview

This technical overview evaluates the performance characteristics of the Agilent 1290 Infinity II Multisampler. Key goals include:

• Assessing area precision under isocratic and gradient conditions over a wide injection-volume range
• Testing system behavior at ultrahigh pressures and flow rates
• Measuring carryover using challenging analytes (chlorhexidine, caffeine)
• Quantifying injection-volume linearity for 40 µL and 100 µL metering devices
• Comparing performance to the preceding 1290 Infinity Autosampler

Methodology and Instrumentation

Performance tests were conducted on a complete Agilent 1290 Infinity LC system equipped with a diode-array detector, binary pump, thermostatted column compartment and the Infinity II Multisampler module. Chromatographic conditions included isocratic runs (water/acetonitrile, 45:55) at flow rates from 0.3 to 2.5 mL/min (up to 1,032 bar), gradient methods (20–95 % B in 5 min), and ultrafast gradients (5–95 % B in 0.5 min). Carryover was assessed with 1,200 ng chlorhexidine and 2,500 ng caffeine injections followed by blank washes. Injection linearity was tested across 0.5–100 µL using external needle wash and Agilent OpenLAB CDS software.

Used Instrumentation

• Agilent 1290 Infinity II Multisampler (40 µL and 100 µL devices)
• Agilent 1290 Infinity Diode Array Detector (10-mm cell)
• Agilent 1290 Infinity Thermostatted Column Compartment
• Agilent 1290 Infinity Binary Pump
• Columns: ZORBAX RRHD SB-C18, Poroshell EC-C18, Eclipse Plus RRHD C18

Main Results and Discussion

Area precision under isocratic conditions was below 0.14 % RSD for 0.5–3 µL injections (40 µL device) and below 0.3 % RSD for larger volumes (100 µL device). At ultrahigh pressure (1,032 bar), 50 µL injections yielded <0.06 % RSD for major peaks. Gradient runs showed <0.14 % RSD above 0.5 µL and <1.5 % RSD at 0.25 µL. Under ultrafast conditions, the Infinity II Multisampler outperformed its predecessor by a factor of 1.5–5.8 in area precision. Carryover tests revealed no detectable residual signal after high-concentration injections. Injection-volume linearity was excellent across the entire range, with RSDs <1.2 % and correlation coefficients approaching unity.

Benefits and Practical Applications

The multichannel design and flexible metering options enable rapid sample throughput with exceptional reproducibility. Minimal carryover and broad volume linearity support quantitative assays in pharmaceutical analytics, food and environmental monitoring, and high-capacity screening operations.

Future Trends and Applications

Ongoing developments may integrate online sample preparation, microfluidic autosamplers and AI-driven method optimization to further streamline workflows. The growing interest in miniaturized UHPLC and fully automated laboratories will benefit from next-generation multisampler platforms.

Conclusion

The Agilent 1290 Infinity II Multisampler demonstrates outstanding precision, flexibility and carryover control across demanding chromatographic regimes. By surpassing established autosampler benchmarks and delivering reliable performance from nanoliter to hundreds of microliters, it represents a versatile solution for modern analytical challenges.