The Chromatography Checklist

Importance of the Topic

Liquid chromatography remains a cornerstone technique in analytical chemistry for separating, identifying, and quantifying components in complex mixtures. Reliable operation depends on rigorous sample preparation, method design, instrument maintenance, and column management to achieve high sensitivity, reproducibility, and minimal downtime.

Objectives and Article Overview

This document presents a comprehensive checklist and best practices for every stage of a chromatographic workflow. It guides the user through sample readiness, supplies management, instrument upkeep, method conditions, column selection, and final shutdown procedures to ensure consistent analytical performance.

Methodology

The workflow begins with assessing sample solubility, filtration, and cleanup techniques such as solid phase extraction (SPE), QuEChERS dispersive SPE, and Captiva EMR-Lipid for combined protein precipitation and lipid removal. It continues with instrumentation checks and maintenance schedules for pumps, autosamplers, detectors, and connections. Method development covers mobile phase preparation, buffer selection (volatile and non-volatile), dwell volume determination, and gradient timing. Column equilibration steps and guard column usage are also detailed.

Used Instrumentation

• UHPLC systems with Agilent high-pressure and isocratic pumps (PTFE frits, pump seals, filters).
• Autosampler modules with rotor seals, metering device seals, and in-line filters.
• Detectors: UV/Diode array, mass spectrometer (ion source maintenance), refractive index, ELSD, fluorescence, and electrochemical.
• InfinityLab Quick Connect and QuickTurn fittings, solvent inlet filters, Stay Safe venting caps.
• Captiva filtration products, EMR-Lipid cartridges and 96-well plates.
• Bond Elut SPE cartridges and 96-well SPE plates.
• Agilent A-Line 2 mL vials and compatible septa.

Main Results and Discussion

Comparative data demonstrate that advanced cleanup (e.g., Captiva EMR-Lipid) yields relative standard deviations below 3 %, improved peak areas, and reduced ion suppression versus simple protein precipitation (>25 % RSD). Variations in mobile phase preparation (order of mixing solvents, buffer concentration) significantly affect retention times, peak shape, and resolution. Regular maintenance and proper fittings reduce dead volume, leaks, and performance drift.

Benefits and Practical Applications

• Enhanced sensitivity and selectivity through targeted matrix removal techniques.
• Extended instrument uptime and reduced service costs via scheduled pump, detector, and autosampler maintenance.
• Greater reproducibility and data quality from consistent mobile phase preparation and system equilibration.
• Protection and longer lifetime of columns achieved with guard cartridges and in-line filters.

Future Trends and Opportunities

• Next-generation sorbents combining multiple cleanup mechanisms for faster, more selective sample preparation.
• Automation of sample prep and remote diagnostics for predictive maintenance.
• Green chromatography approaches using minimal solvents and energy-efficient workflows.
• Integration of artificial intelligence for method optimization and real-time performance monitoring.

Conclusion

A structured checklist spanning sample preparation to shutdown ensures robust and efficient chromatographic analyses. Adherence to best practices in method design, instrumentation care, and column management delivers reproducible results and protects valuable analytical assets.

References

• No references provided in the source document.