Drugs of abuse in hair: high speed and sensitivity demands for LC-MS/MS

Importance of the Topic

Hair analysis for drugs of abuse offers a prolonged detection window compared to blood or urine, enabling identification of chronic substance use over months. This approach meets growing demands in regulatory compliance, forensic investigations, and professional fitness assessments, such as traffic safety screenings.

Goals and Study Overview

This work presents a high-throughput LC-MS/MS strategy for simultaneous screening and confirmation of 14 drugs of abuse and metabolites in human hair. The method addresses stringent Brazilian National Traffic Council guidelines requiring low cutoff values and rapid processing to support large-scale testing.

Methodology

• Sample Preparation for Screening/Confirmation: 10 mg of washed hair cut into ~1 mm segments; extracted with acidified organic solvent under heat (1 h 45 min) followed by 15 min ultrasonic bath; batch processing enables hundreds of samples simultaneously.
• THC-COOH Confirmation: 30 mg hair digested and extracted with hexane:ethyl acetate; extended chromatographic run to minimize matrix suppression.
• Chromatography: 1.7-minute cycle (2.1-minute injection-to-injection) for screening and confirmation of 14 analytes, including isomeric separation of benzoylecgonine and norcocaine; longer runtime for THC-COOH.

Used Instrumentation

• Shimadzu LCMS-8060NX triple quadrupole mass spectrometer
• Nexera X3 UHPLC system with C18 analytical column

Results and Discussion

The method achieved limits of quantitation below regulatory cutoffs for all target compounds, with linear calibration curves exhibiting R²>0.99. Key findings include:

• LOQs met or exceeded required thresholds (e.g., 0.1 pg/mg for THC-COOH).
• Robust quantitation at 50–200% of cutoff levels for screening.
• Clear chromatographic separation and reproducible peak shapes for all analytes.

Benefits and Practical Applications

This LC-MS/MS approach delivers high sensitivity and speed, reducing per-sample cost and time while supporting mandatory drug testing in traffic safety, workplace monitoring, and forensic toxicology. The streamlined sample preparation and sub-2-minute analyses enable large laboratories to handle elevated sample volumes with confidence.

Future Trends and Potential Uses

Advancements may include integration of automated sample handling, expanded analyte panels for emerging psychoactive substances, and enhanced data processing with machine learning. Coupling high-resolution mass spectrometry could further improve identification specificity in complex matrices.

Conclusion

The described LCMS-8060NX method provides a reliable, rapid, and sensitive solution for hair-based drug screening and confirmation, fulfilling regulatory requirements and supporting large-scale toxicological testing with minimal turnaround times.