Comparison of the Agilent 1260 Infinity Autosampler with the Standard Autosampler

Importance of the topic

High-performance liquid chromatography (HPLC) plays a crucial role in pharmaceutical quality control and method development, where reproducible retention times, peak areas, and sensitivity are mandatory under regulated environments. The ability to upgrade existing systems without extensive revalidation offers laboratories cost-effective paths to improved throughput, compactness, and integrated temperature control.

Objectives and study overview

This study compares the performance of three Agilent 1260 Infinity configurations in the analysis of six antiepileptic compounds. The aim is to demonstrate backward compatibility between the original 1260 Infinity Standard Autosampler and the newer 1260 Infinity Autosampler, both with and without the optional integrated column compartment.

Used instrumentation

Configuration A (Standard Autosampler):

• 1260 Infinity Binary Pump with solvent selection valve
• 1260 Infinity Standard Degasser
• 1260 Infinity Standard Autosampler
• 1290 Infinity Thermostat
• 1260 Infinity Thermostatted Column Compartment (G1316A)
• 1260 Infinity Diode Array Detector (Max-Light cartridge cell)

Configuration B (Autosampler + Cooler):

• 1260 Infinity Binary Pump with solvent selection valve
• 1260 Infinity Standard Degasser
• 1260 Infinity Autosampler with sample cooler
• 1260 Infinity Thermostatted Column Compartment
• 1260 Infinity Diode Array Detector

Configuration C (Autosampler with integrated column compartment):

• Same as B, but with integrated 3 µL heater column compartment replacing G1316A

Methodology

A mixture of 2-ethyl-2-phenylmalonamide, ethosuximide, primidone, α-methyl-α-phenyl succinimide, phenytoin, and carbamazepine was separated on a ZORBAX SB-C18 column (4.6 × 150 mm, 5 µm) at 60 °C. The gradient (0.8 mL/min) ranged from 15 % to 95 % acetonitrile over 20 min. Samples were maintained at 8 °C and injected at 5 µL. Detection was performed at 204 nm (reference 360 nm). Eight calibration levels (0.78–200 ng/µL) were injected in triplicate, and limits of detection (LOD) and quantification (LOQ) were determined (S/N > 3 and > 10). Ten consecutive injections of 25 ng/µL were used to assess retention time (RT) and area precision and resolution.

Main results and discussion

Across all three configurations:

• RT RSDs were below 0.07 % and area RSDs below 0.23 % for all compounds.
• Resolution remained high (> 2.8 for carbamazepine to > 33 for succinimide).
• Correlation coefficients exceeded 0.999 for all calibration curves.
• LODs ranged from 0.1 to 1.9 ng on column, and LOQs from 0.3 to 6.2 ng.
• Configuration C showed slight RT shifts (up to 2.4 %) but maintained analytical performance.

This confirms that the 1260 Infinity Autosampler, even with the integrated column compartment, delivers equivalent UHPLC performance while offering a reduced footprint and added temperature control.

Benefits and practical applications

• Backward compatibility minimizes revalidation effort in regulated labs.
• Integrated cooling and column compartment reduce system height and external modules.
• Extended sample capacity and faster injection cycles improve throughput.
• Maintained precision and sensitivity support routine QC of pharmaceuticals.

Future trends and potential applications

Further integration of modules will drive smaller footprints and simplified workflows. Automation of method transfer and robustness checks could enhance routine analysis. Coupling with mass spectrometry and advanced data handling will expand applications in metabolomics, therapeutic drug monitoring, and high-throughput screening.

Conclusion

The Agilent 1260 Infinity Autosampler, with or without its integrated column compartment, matches the analytical performance of the original Standard Autosampler in terms of precision, resolution, linearity, and sensitivity. Laboratories can upgrade to a more versatile, compact system with minimal revalidation, thereby improving operational efficiency and capacity.

References

1. Agilent 1260 Infinity Autosampler, Agilent Technologies Data Sheet, publication number 5991-6287EN, 2015.
2. Agilent 1260 Infinity Standard Autosampler, Agilent Technologies Data Sheet, publication number 5990-6120EN, 2010.
3. Schneider S. Analysis of Pharmaceutical Substances Using HPLC and UHPLC Methods, Agilent Technologies Application Note, publication number 5991-5847EN, 2015.
4. Huber U. Analysis of Antiepileptic Drugs by HPLC, Agilent Technologies Application Note, publication number 5968-1119EN, 2001.