Determination of multiple pesticide residues in animal foods using on-line gel permeation chromatography-gas chromatography/mass spectrometry

Importance of the Topic

Accurate determination of pesticide residues in animal foods is critical to ensure food safety and regulatory compliance. Animal-derived products often contain complex matrices rich in fats and pigments that can interfere with analysis.

Objectives and Study Overview

This study developed a modified QuEChERS extraction coupled with on-line gel permeation chromatography and gas chromatography mass spectrometry for simultaneous determination of 21 pesticide residues in animal foods. Method validation was performed in pork and shrimp matrices to assess sensitivity, recovery, and precision.

Methodology

Sample pretreatment involved homogenization with water, extraction using acetonitrile and n-hexane, salt-induced phase separation, and cleanup with PSA and C18 sorbents. The cleaned extract was directly introduced into the GPC-GC/MS system for analysis.

Instrumentation Used

GPC conditions: acetone/cyclohexane mobile phase, Shodex CLNpak EV-200 column, flow rate 0.1 mL/min, 40 °C. GC/MS conditions: Rxi-5ms analytical column with precolumn, PTV injector with temperature program up to 250 °C, oven ramp from 82 °C to 300 °C, electron impact ionization, SIM mode for target pesticides.

Results and Discussion

The combined method effectively removed fats and pigments, reducing matrix background. Recoveries at 0.02 mg/kg ranged from 72.9% to 118.6% with relative standard deviations below 10%. Limits of detection and quantification were 0.6 to 2.5 µg/kg and 2.0 to 8.4 µg/kg, respectively, demonstrating adequate sensitivity and linearity for routine monitoring.

Benefits and Practical Applications

• Automated cleanup reduces manual handling and variability
• High throughput for regulatory and quality control laboratories
• Sufficient sensitivity to meet residue limits in animal food matrices

Future Trends and Potential Applications

Future developments may include integration with tandem mass spectrometry for broader analyte coverage, adaptation to diverse food matrices, miniaturization for field analysis, and implementation of advanced data processing algorithms for rapid screening.

Conclusion

The proposed on-line GPC-GC/MS method with modified QuEChERS extraction provides a simple, rapid, and reliable approach for multi-residue pesticide analysis in animal foods, supporting food safety and regulatory compliance.

References

No references were provided in the original document.