Overview of SPE Technology/Method Development & New Trends in Sample Preparation

Importance of Sample Preparation

Effective sample preparation is essential to achieve accurate, precise and reliable chromatographic and mass spectrometric results. It removes interferences, concentrates target analytes and adapts complex matrices to analytical systems, extending column lifetime and improving signal‐to‐noise ratios.

Objectives and Overview

This presentation provides a comprehensive survey of solid‐phase extraction (SPE) technologies, retention mechanisms and a systematic approach to method development. It illustrates new sample preparation trends and multi‐residue protocols for diverse matrices.

Methodology and Instrumentation

• Fundamentals of SPE: reversed-phase, normal-phase, ion-exchange and mixed-mode chemistries.
• Key SPE workflow steps: conditioning, equilibration, sample loading, washing, elution, evaporation and reconstitution.
• Retention control via pH and organic solvent strength adjustments.
• Instrument platforms: cartridges, 96-well plates, vacuum manifolds and robotic systems (Zymark RapidTrace, TomTec Quadra, Gilson SPE 215).
• Analytical detection: HPLC-UV, GC-MS, LC-MS/MS and fluorescence.

Main Results and Discussion

• Systematic SPE development on C18 and cyano phases yielded high recoveries (>90%) and low RSDs (<4%) for tricyclic antidepressant analysis in serum, outperforming generic polymeric methods.
• Optimized wash/elution conditions (e.g. 40% MeOH in basic buffer for wash; 60% MeOH elution) improved selectivity and minimized interferences.
• Tailored SPE protocols enabled quantitative extraction of furosemide from serum down to 0.5 µg/mL using direct injection of diluted eluate.
• Cyano SPE outperformed C18 in steroid extraction from urine, providing cleaner baselines and robust recoveries (>90%).
• Multi-residue workflows on mixed-mode and molecularly imprinted polymer (MIP) media enabled selective isolation of pharmaceuticals and beta-agonists in complex biological fluids.

Benefits and Practical Applications

• Highly selective cleanup reduces matrix effects, ion suppression and column fouling.
• Low solvent consumption and compatibility with automation accelerate throughput.
• Flexible SPE formats support bioanalysis, environmental testing, food safety and forensic applications.

Future Trends and Applications

• Molecularly imprinted polymers for ultra-selective extractions and lower detection limits.
• High-throughput SPE method development plates for parallel optimization of pH and organic strength.
• Emerging formats: SPE disks, reversible cartridges, on-line SPE coupling and stir-bar sorptive extraction (SBSE).
• Integration with QuEChERS workflows and advanced robotic platforms for multi-residue analysis.

Conclusion

Solid-phase extraction remains a cornerstone of modern analytical workflows. By systematically controlling retention parameters and leveraging novel sorbents and formats, laboratories can achieve superior cleanup, reproducibility and sensitivity across diverse sample types.

References

• Majors RE. New Sample Prep Technologies for the Sample Prep Industry. 2006, GMP Training Systems.
• Wells DA. High Throughput Bioanalytical Sample Preparation. Elsevier, 2003.
• Simpson NJK, Ed. Solid-Phase Extraction: Principles, Techniques, Applications. Marcel Dekker, 2000.
• Fritz JS. Analytical Solid-Phase Extraction. John Wiley & Sons, 1999.
• Wiltshire H. In: Venn RF, Ed. Principles and Practice of Bioanalysis. Taylor & Francis, 2000.