Simultaneous Determinations of 17 abused drugs and organophosphorus pesticides in human blood by GPC-GCMS

Importance of the Topic

Rapid and reliable detection of multiple drug and pesticide residues in human blood is critical for forensic toxicology, clinical diagnostics, and environmental health monitoring. Simultaneous analysis reduces turnaround time and conserves sample volume while ensuring accurate exposure assessment.

Objectives and Study Overview

The study aimed to develop and validate an integrated sample preparation and analysis workflow combining a modified QuEChERS extraction with on-line gel permeation chromatography–gas chromatography/mass spectrometry (GPC-GC/MS). This approach targets 17 abused drugs and organophosphorus pesticides in human blood with minimal manual cleanup and high throughput.

Methodology and Used Instrumentation

The sample preparation employed a modified QuEChERS protocol:

• Extraction from 2 mL blood with acetonitrile
• Cleanup using PSA, C18, and MgSO4 sorbents
• Solvent evaporation and reconstitution in GPC mobile phase

On-line GPC conditions:

• Column: Shodex CLNpak EV-200 (2 mm ID × 150 mm)
• Mobile phase: acetone/cyclohexane (3:7 v/v) at 0.1 mL/min
• Oven temperature: 40 °C; injection volume: 20 µL

GC–MS parameters:

• Column setup: deactivated silica tubing (0.53 mm ID × 5 m) + Rtx-5ms pre-column and analytical column (0.25 mm ID × 30 m, 0.25 µm film)
• PTV injector with temperature program from 120 °C to 250 °C
• Oven ramp: 82 °C hold, 8 °C/min to 300 °C
• Ion source at 210 °C, interface at 280 °C, SIM acquisition mode

Main Results and Discussion

The method demonstrated:

• Linearity with correlation coefficients >= 0.997 over 50–1000 µg/L
• Limits of detection from 0.001 to 0.012 mg/L and quantification from 0.003 to 0.036 mg/L
• Recoveries between 70% and 115% with relative standard deviations ≤ 5% at spiking levels of 0.05 and 0.5 µg/mL
• Efficient removal of proteins, lipids, and pigments, reducing matrix interferences and enhancing sensitivity

Benefits and Practical Applications

This GPC-GC/MS approach offers:

• Rapid sample turnaround and reduced manual workload
• High selectivity and sensitivity for simultaneous multi-residue analysis
• Robust performance suitable for forensic, clinical, and QA/QC laboratories

Future Trends and Potential Applications

Further developments may include automation of the QuEChERS cleanup, extension to other biological matrices (urine, tissues), integration with high-resolution mass spectrometry, and adoption of greener solvents to improve throughput and sustainability.

Conclusion

The validated on-line GPC-GC/MS method coupled with modified QuEChERS extraction provides a fast, reliable, and sensitive platform for simultaneous determination of abused drugs and organophosphorus pesticides in human blood, fulfilling stringent analytical criteria and enabling broad forensic and clinical applications.

Reference

• Sun Qian, Fan Jun, Huang Taohong, Kawano Shin-ichi, Hashi Yuki. Simultaneous Determinations of 17 Abused Drugs and Organophosphorus Pesticides in Human Blood by GPC-GC/MS. Pittcon 2014, Poster 1090-14P.