Drug Screening in Whole Blood Using a High-Resolution LC/Q-TOF and Novel Software Screener Tool

Importance of the topic

Modern forensic and clinical laboratories face a growing array of illicit, prescription and over-the-counter compounds that require rapid, reliable detection in complex matrices such as whole blood. A flexible, high-throughput workflow that can adapt to newly emerging drugs without extensive method redevelopment is essential to maintain timely and accurate screening across diverse applications.

Study Objectives and Overview

This work evaluates a comprehensive workflow combining automated sample preparation, high-resolution LC/Q-TOF mass spectrometry operated in data-independent acquisition mode, and a novel data analysis tool (LC Screener) for routine drug screening in whole blood. The goals were to achieve low matrix effects, high analyte recoveries, robust chromatographic separation of 153 target compounds, and straightforward data review and reporting.

Methodology and Instrumentation

The study employed solid-phase extraction on Captiva EMR-Lipid 96-well plates with a Bravo Automated Liquid Handling Platform for minimal user intervention and improved reproducibility. Samples comprised blood spiked with 153 analytes and ten deidentified forensic specimens. Chromatographic separation was performed on an Agilent 1290 Infinity II system using a 10-minute gradient. Detection utilized an Agilent 6546 LC/Q-TOF with an AJS ion source in positive mode (m/z 40–1000, collision energies 20 and 40 eV, acquisition rate 8 Hz) under data-independent acquisition. Data analysis and screening were conducted in MassHunter Quantitative Analysis 10.1 with the LC Screener Tool, applying criteria of mass accuracy ≤ 5 ppm, signal-to-noise ≥ 3, retention time tolerance ± 10%, co-elution ≥ 80% and at least two fragment matches.

Main Results and Discussion

• Matrix Effects and Recoveries

• 77% of analytes exhibited matrix suppression below 10%.
• 91% of compounds demonstrated recoveries between 70% and 130%.
• Cannabinoids showed slightly lower recoveries due to their chemistry.

• Chromatographic Performance

• Rapid 10-minute LC method resolved 153 analytes, including baseline separation of six isobaric pairs.
• High acquisition speed provided ≥12 data points per peak without compromising resolution or mass accuracy.

• Sensitivity and Robustness

• 91% of analytes were reproducibly detected as positive at 5 ng/mL or lower in six replicates without sample concentration.
• Ten real forensic samples yielded multiple positive parent drugs and metabolites.
• A 1,465-injection robustness test showed stable retention times, mass accuracy and signal intensities with minimal maintenance.

• Data Analysis and Reporting

• LC Screener Tool streamlined identification, categorizing compounds as positive, needs review or negative based on preset criteria.
• Simultaneous quantitation of common analytes was achievable within the same workflow.

Benefits and Practical Applications

• Dynamic addition of new analytes without method redevelopment due to DIA capability.
• Automated sample preparation reduces manual handling errors and enhances throughput.
• High-resolution MS ensures confident identification in complex whole blood matrices.
• Integrated screening and quantitation accelerate reporting in forensic, clinical and QA/QC settings.

Future Trends and Opportunities

Advances may include expanded spectral libraries, AI-driven data interpretation, adaptation to other biological matrices (urine, saliva, tissues), miniaturized and point-of-care platforms, and real-time direct sampling approaches to further enhance speed, sensitivity and adaptability of drug screening workflows.

Conclusion

The combined use of automated solid-phase extraction, a high-resolution LC/Q-TOF operated in DIA mode, and the LC Screener Tool provides a robust, flexible, and high-throughput workflow for comprehensive drug screening in whole blood. This approach delivers low matrix effects, high recoveries, reliable sensitivity and streamlined data analysis suited to forensic and clinical laboratories.

References

Yannell KE, Gomes M. Drug Screening in Whole Blood Using the Agilent 6546 LC/Q-TOF and the LC Screener Tool with Automated Sample Preparation. Agilent Technologies; March 20, 2020.