NEMC: Recent Advances in Sample Preparation by a New Accelerated Solvent Extraction Technique

Importance of the Topic

Sample preparation remains a major bottleneck in analytical chemistry, impacting throughput, reproducibility, and cost. Innovations in accelerated solvent extraction (ASE) improve control over extraction parameters, reduce solvent usage, and enable seamless integration of extraction and concentration steps, thereby enhancing laboratory efficiency and data quality.

Objectives and Study Overview

This work introduces a next-generation ASE system combining three advances: gas assisted extraction for enhanced solvent efficiency and control; four-channel parallel extraction to boost throughput; and fully automated concentration with machine-learning driven end-point detection. The aim is to demonstrate improved performance metrics across diverse sample types and workflows.

Methodology

The new ASE platform operates in three modes:

• Gas Assisted Extraction: Alternating pulses of solvent and compressed N₂ at controlled flow rates and pressures to optimize analyte desorption.
• Parallel Extraction: Four independent extraction cells operating simultaneously under individual ovens for walk-away sample preparation.
• Integrated Concentration: Vacuum and nitrogen deliver direct evaporation into autosampler vials, with image-based machine learning detecting the desired end-point volume automatically.

Instrumentation Used

• Accelerated Solvent Extraction unit with solvent blending (up to six solvents).
• Proportioning valve and compressed nitrogen source for gas assisted operation.
• Four-channel extraction chamber with independent oven controls.
• Integrated vacuum pump and nitrogen manifold for evaporation.
• Image sensor and backlighting assembly coupled with machine-learning software for end-point detection.

Main Results and Discussion

Gas assisted extraction reduced solvent consumption by up to 50% versus traditional ASE, while delivering lipid recoveries exceeding 95% at optimized N₂ pressures. Parallel four-channel extraction increased daily sample throughput to 48 samples (10 mL cells), compared to 36 samples with conventional automated methods. Machine-learning driven evaporation achieved precise final volumes without manual intervention, ensuring consistent concentration and minimizing carry-over.

Benefits and Practical Applications

The combined system offers:

• Significant solvent and labor cost savings.
• Enhanced reproducibility through automated control of pressure, temperature, and flow.
• High throughput via parallel processing and true walk-away operation.
• Seamless integration into LC/GC workflows by concentrating directly into autosampler vials.
• Automated sample tracking and reduced risk of human error.

Future Trends and Opportunities

Ongoing developments may include expanded solvent blending capabilities, coupling with real-time analytics, broader adoption of machine learning for process control, and integration with laboratory information management systems (LIMS). Recycling of spent solvents and miniaturization of extraction cells could further enhance sustainability and sample throughput.

Conclusion

The novel ASE platform combining gas assisted extraction, parallel processing, and automated concentration addresses key challenges in modern laboratories. It delivers improved efficiency, reproducibility, and cost-effectiveness, enabling analysts to focus on data interpretation rather than routine sample preparation tasks.

References

• US Patent 9,440,166 B2: Gas assisted extraction mechanism and control.
• US Patent 11,123,655 B2: Four-channel automated extraction design.