Screen More Drugs with the Agilent GC/MS Toxicology Analyzer with a High Efficiency Source

Significance of the Topic

Broad-range screening for drugs in biological samples is essential in forensic toxicology to ensure accurate identification of known and unknown compounds at trace levels. Enhancing sensitivity and spectral clarity supports reliable case outcomes and expands the scope of detectable analytes.

Study Objectives and Overview

This study evaluates the performance of the Agilent GC/MS Toxicology Analyzer equipped with a High Efficiency Source (HES) and Deconvolution Reporting Software (DRS) against a conventional extractor source. The goal is to demonstrate improved drug detection at lower concentrations, maintain robust library matching, and reduce analysis time without derivatization.

Methodology

• Sample preparation: 2 mL of human serum extracted using Agilent Bond Elut Certify general drug screen method.
• Sample processing: Extracts reconstituted in 0.1 mL methanol and spiked with GC/MS Toxicology Checkout Mixture to yield 10–1000 ng/mL standards.
• Analysis: Full-scan GC/MS with Agilent 7890A GC and 5977B Mass Selective Detector operated in HES autotune and conventional extractor etune modes.
• Data processing: AMDIS deconvolution with a minimum match factor of 75 using the Forensic Toxicology Database Library.

Instrumentation

• Agilent 7890A Gas Chromatograph coupled to 5977B Mass Selective Detector.
• High Efficiency Source (HES) for enhanced ion formation and transfer.
• Deconvolution Reporting Software (DRS) and Forensic Toxicology Database Library for spectral identification.

Key Results and Discussion

• The HES configuration achieved significantly lower detection limits compared to the extractor source, detecting compounds such as MDEA and meperidine down to 0.5 ng/mL (equivalent to 10 pg injected).
• Overlayed total ion chromatograms demonstrated up to an order of magnitude higher signal intensity with HES, improving identification confidence.
• NIST library matching of cocaine at 100 pg in serum yielded a match factor of 810, clearly differentiating isomers and providing NIST-searchable spectra.
• Full-scan mode with HES approaches the sensitivity of SIM methods while eliminating derivatization steps.

Benefits and Practical Applications

• Enhanced sensitivity and broader screening capabilities support comprehensive toxicological analysis in forensic and clinical laboratories.
• Improved spectral quality and library matching enable confident identification of target and nontarget compounds, including isomer differentiation.
• Reduced sample preparation time and increased throughput by avoiding derivatization and leveraging full-scan acquisition.

Future Trends and Potential Applications

Emerging opportunities include integrating HES-enhanced GC/MS workflows with expanded spectral databases, automating data processing for high-throughput environments, and applying the technology to novel psychoactive substances and environmental monitoring. Combining HES with other mass spectrometric modalities could further broaden analytical coverage and specificity.

Conclusion

The integration of Agilent’s High Efficiency Source on the 5977B GC/MSD with Deconvolution Reporting Software markedly improves broad-range drug screening by lowering detection limits, providing classical NIST-searchable spectra, and streamlining workflows without derivatization.

References

• Agilent Technologies, Inc. Agilent Bond Elut Certify and Certify II Methods Manual; Publication number 5991-4939EN, 2014.
• Schlesinger HL. Topics in the Chemistry of Cocaine. B. Narcotics. 1985;1:63-78.
• National Institute of Standards and Technology. NIST/EPA/NIH Mass Spectral Library (NIST 14) and Mass Spectral Search Program (Version 2.2) User’s Guide. U.S. Department of Commerce.