Automated Disposable Pipette Extraction - DPX

Significance of the topic

Disposable Pipette Extraction (DPX) represents a transformative approach to solid phase extraction, offering rapid, efficient sample preparation and minimizing solvent consumption and manual steps, thus addressing critical bottlenecks in analytical workflows.

Objectives and overview

This article introduces the DPX technique, details its operational principles, describes integration with Gerstel MPS automation and MAESTRO software, and illustrates its application in GC/MS and LC/MS systems for high-throughput drug screening and pesticide analysis.

Methodology and instrumentation

DPX employs disposable pipette tips containing loose sorbent that is dynamically mixed with the sample via turbulent air bubbles for optimal contact and rapid extraction. Elution into a small solvent volume concentrates analytes without requiring traditional conditioning or evaporation steps. Automation is achieved using the Gerstel MPS PrepStation controlled by MAESTRO software, with subsequent analysis on GC/MS and LC/MS/MS platforms including Agilent 1200 HPLC, Zorbax Eclipse Plus C18 column, and Agilent 6410 Triple Quad mass spectrometer.

Main results and discussion

DPX demonstrated near-quantitative recoveries and low relative standard deviations (<15%) for a range of drugs of abuse in whole blood and urine. Total ion and extracted ion chromatograms showed clean baselines and low detection limits using minimal sample volumes. Automatic in-inlet derivatization for cannabinoids and benzodiazepines further streamlined workflows. A DPX-LC/MS/MS method enabled simultaneous screening of 40 drugs in urine with recoveries from 47% to 145% and high throughput via multiple reaction monitoring.

Benefits and practical applications

Key advantages of DPX include extraction and elution in seconds without conditioning, small eluent volumes enabling concentrate-and-inject strategies, compatibility with large volume injections, and fully automated workflows that synchronize sample prep with analytical runs. These features support clinical toxicology, forensic analysis, therapeutic drug monitoring, pesticide residue testing, and QA/QC in industry.

Future trends and potential applications

Future developments may extend DPX to diverse sample matrices, expand sorbent chemistries for broader analyte classes, integrate AI-driven method optimization and real-time monitoring, and miniaturize devices for on-site testing, further enhancing analytical flexibility and speed.

Conclusion

DPX provides a fast, reproducible, and solvent-efficient sample preparation solution fully compatible with automated GC/MS and LC/MS workflows. By eliminating conditioning steps and enabling in-line derivatization, DPX maximizes throughput, sensitivity, and reproducibility across various analytical applications.