Utilizing an Automated Platform to Streamline Workflow Processes: Sample Preparation and Extraction for Definitive Drug Testing on the Hamilton Microlab STAR

Significance of the Topic

Solid-phase extraction is a critical step in forensic toxicology workflows, ensuring reliable and reproducible quantification of drugs of abuse and pain management agents in biological matrices. Automating this process addresses bottlenecks in sample preparation, minimizes human error, and enhances laboratory throughput.

Aim and Overview of the Study

This study demonstrates the transfer of a previously validated SPE method for urine analysis onto the Hamilton Microlab STAR platform. The objectives were to automate sample pretreatment and extraction for a comprehensive panel of analytes, streamline the workflow, and maintain or improve analytical performance compared to manual processes.

Methodology and Instrumentation

The automated SPE workflow uses Oasis MCX µElution plates on the Hamilton Microlab STAR. Key steps include addition of isotope-labeled internal standards in hydrolysis buffer, sample acidification, conditioning, washing, vacuum drying, and elution with organic solvents. The eluate is diluted and shaken before UPLC-MS/MS analysis.
Applied instrumentation:

• Hamilton Microlab STAR with Venus 3 control software
• Waters ACQUITY UPLC I-Class FTN and BEH C18 column
• Xevo TQ-S micro triple quadrupole MS with MassLynx v4.2 and TargetLynx quantification

Main Results and Discussion

Comparative recovery experiments between manual and automated extraction across multiple QC levels and calibration points showed equivalent or improved performance on the automated platform. Inter-day and intra-day precision achieved RSDs below 5% for most analytes, accuracy within ±15% (±20% at the low QC), and correlation coefficients above 0.99, meeting SWGTOX and FDA validation criteria.

Benefits and Practical Applications

The automated method offers:

• High-throughput, reproducible sample preparation
• Reduced analyst-associated errors, including mis-spikes and transfer inconsistencies
• Compliance with regulatory bioanalytical guidelines
• Increased analyst capacity for data review and method development

Future Trends and Opportunities

Opportunities include expanding automated SPE protocols to larger and more diverse analyte panels, integrating inline extraction with direct coupling to mass spectrometers, implementing advanced scheduling for continuous operation, and adapting workflows for next-generation high-resolution platforms.

Conclusion

Automation of SPE on the Hamilton Microlab STAR delivers a robust, reproducible, and efficient sample preparation solution for quantitative drug testing in urine. The approach minimizes manual errors, meets stringent validation criteria, and supports high-throughput forensic toxicology applications.

Reference

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• Danaceau J.P. et al., Comprehensive Method for Pain Management Drugs and Drugs of Abuse, Waters Application Note 720006187EN, 2019.
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