Extraction of Illicit Drugs and Pesticides from Liver Tissue Using ISOLUTE® SLE+ Prior to GC/MS Analysis

Significance of the Topic

The combined extraction of illicit drugs and pesticides from tissue matrices is essential in forensic toxicology and environmental health. A streamlined protocol reduces analysis time, solvent consumption and improves laboratory throughput.

Objectives and Study Overview

This work aimed to develop and validate a supported liquid extraction method using ISOLUTE SLE+ columns for simultaneous isolation of diverse drug and pesticide classes from liver tissue prior to GC/MS detection.

Methodology

Sample Preparation

• Homogenize 200 mg liver in 50:50 methanol-water with 2.8 mm ceramic beads using Biotage Lysera for 30 seconds at 5.3 m/s.
• Centrifuge at 13 300 rpm for 10 minutes and collect the supernatant.
• Load 500 µL of supernatant onto an ISOLUTE SLE+ 1 mL column; initiate flow under a brief pulse of vacuum or positive pressure.
• Elute analytes with two 2.5 mL aliquots of dichloromethane, stabilizing basic compounds with 0.2 M HCl in methanol.
• Evaporate extracts under air or nitrogen, reconstitute in ethyl acetate, then derivatize with MSTFA at 80 °C for 30 minutes.

Used Instrumentation

• Biotage Lysera tube homogenizer with ceramic beads.
• ISOLUTE SLE+ 1 mL supported liquid extraction columns.
• Agilent 7890A gas chromatograph with J&W DB-5 column (30 m × 0.25 mm × 0.25 µm).
• Agilent 5975C mass selective detector operating in selected ion monitoring (SIM) mode.

Main Results and Discussion

Recoveries for 26 analytes—including amphetamines, barbiturates, benzodiazepines, organochlorine, organophosphate, pyrethroid, triazine pesticides and cannabinoids—were consistently high with relative standard deviations below 10 percent. Calibration curves over 50 to 2500 ppb yielded coefficients of determination between 0.9931 and 0.9995. Most compounds reached a lower limit of quantitation of 50 ppb, with a few analytes requiring 100 ppb or higher.

Benefits and Practical Applications

• Efficient extraction without emulsion formation and minimal matrix interference.
• High-throughput capability suitable for routine screening.
• Reduced solvent consumption and simplified workflow compared to traditional liquid-liquid extraction.

Future Trends and Potential Applications

Prospective developments include integration with automated liquid-handling systems, extension to other tissue or complex matrices, and coupling with high-resolution mass spectrometry for enhanced selectivity. Innovations in SLE sorbent design may further improve recovery rates and lower detection thresholds.

Conclusion

The presented ISOLUTE SLE+ protocol offers a robust, sensitive and reproducible workflow for the simultaneous extraction of illicit drugs and pesticides from liver tissue, delivering clean extracts, reliable quantitation and streamlined operations for forensic and industrial laboratories.