Analysis of Toxicological Substances in Whole Blood Using the Smart Forensic Database (2)

Importance of the Topic

Gas chromatography–mass spectrometry (GC–MS) remains a fundamental tool in forensic and clinical toxicology for detecting and quantifying a wide range of poisons and drugs in biological matrices. The integration of comprehensive spectral and MRM databases accelerates method development and enhances confidence in compound identification, supporting timely decision making in medical and legal settings.

Study Objectives and Overview

This work demonstrates the application of Shimadzu’s Smart Forensic Database and GC/MS Forensic Toxicological Database in a combined Scan/MRM acquisition strategy to analyze toxicological substances in whole-blood samples. The goals were to streamline method creation, achieve broad coverage of target analytes, and validate identification using complementary database searches.

Methodology and Instrumentation Used

Sample Preparation

• Whole-blood aliquots (1 mL) were fractionated into acidic (pH 5) and basic (pH 9) extracts via liquid-liquid extraction on EXtrelut NT3 cartridges.
• Each fraction was eluted with a chloroform–isopropanol (3:1) mixture, combined, dried over silica gel, and reconstituted in 200 µL of the same solvent.

GC–MS/MS Conditions

• Instrument: GCMS-TQ8040 with Smart Forensic Database for automatic Scan/MRM method generation.
• Column: Rxi-5SilMS, 30 m × 0.25 mm × 0.25 µm.
• Injection: splitless at 260 °C, 1 µL.
• Oven program: 60 °C hold 2 min, ramp 10 °C/min to 320 °C, hold 15 min.
• Carrier gas: linear velocity 45.6 cm/s.
• MS settings: interface 280 °C, ion source 200 °C; simultaneous Scan (m/z 43–600, 10 000 u/s) and MRM (0.3 s/event) with 0.4 s loop time.

Key Results and Discussion

A simultaneous Scan/MRM analysis of a whole-blood extract enabled the targeted detection of 201 compounds via MRM transitions and broader screening of approximately 1 400 substances using the GC/MS Forensic Toxicological Database. Pentederone, a cathinone derivative, was unambiguously identified by matching its retention index, MRM ratio, and full-scan mass spectrum against database entries. The combined approach offers both quantitative reliability and qualitative confirmation in a single run.

Benefits and Practical Applications of the Method

• Rapid method development: Automatic Scan/MRM method creation from a curated database minimizes manual optimization.
• Comprehensive coverage: Simultaneous targeted and nontargeted workflows detect known and unexpected toxicants.
• High confidence: Dual verification through MRM ratio checks and full-scan spectral matching reduces false positives.
• Clinical and forensic utility: Suitable for routine toxicology screening, postmortem investigations, and emergency toxicology.

Future Trends and Potential Applications

• Database expansion: Inclusion of emerging designer drugs and metabolites to keep pace with illicit substance trends.
• High-resolution MS integration: Combining accurate-mass data with retention indices for even greater specificity.
• Artificial intelligence: Machine-learning algorithms to predict retention behavior and automate spectral interpretation.
• Miniaturized and field-deployable systems: Point-of-care toxicology screening in remote or resource-limited environments.

Conclusion

The integration of Smart Forensic and GC/MS Forensic Toxicological Databases in a simultaneous Scan/MRM GC–MS/MS workflow delivers a robust, high-throughput solution for forensic toxicology. By combining targeted MRM quantitation with broad-spectrum full-scan confirmation, this approach enhances analytical confidence and operational efficiency in detecting a wide array of toxic substances in whole blood.

References

• Shimadzu Corporation. LAAN-J-MS-E101, First Edition: September 2014.
• Zaitsu K. Department of Legal Medicine & Bioethics, Nagoya University Graduate School of Medicine, data contribution.