Multi-residue analysis of pesticides in edible oils by triple quadrupole GC-MS

Importance of the topic

Edible oils may contain trace pesticide residues due to agricultural practices and storage. Sunflower oil is widely consumed and valued for its nutritional benefits, making rigorous monitoring of residues critical to ensure food safety and regulatory compliance. High sensitivity and selectivity are required to detect levels at or below maximum residue limits set by authorities.

Objectives and study overview

The study aimed to evaluate the performance of a triple quadrupole gas chromatograph mass spectrometer system for multi-residue analysis of over 300 pesticides in sunflower oil. The configuration included a TSQ 9610 mass spectrometer with an advanced electron ionization source and a TRACE 1610 gas chromatograph coupled to an automated autosampler and splitless injection.

Methodology and instrumentation

Sunflower oil samples were extracted by adding toluene and acetonitrile (60:40), followed by freezing and injection of the supernatant. Quantitation used a six-point matrix-matched calibration curve (5–100 µg/kg) and a standard addition approach to compensate for matrix effects.

Used instrumentation

• TRACE 1610 GC with iConnect splitless inlet module
• TriPlus RSH SMART liquid autosampler
• TraceGOLD TG-35MS column (30 m × 0.25 mm × 0.25 µm)
• TSQ 9610 triple quadrupole MS with NeverVent Advanced Electron Ionization source
• Chromeleon Chromatography Data System for control and data processing

Main results and discussion

• Timed-SRM acquisition delivered high sensitivity and selectivity, resolving 300+ pesticides in complex oil matrix.
• Calibration linearity (5–100 µg/kg) achieved correlation coefficients > 0.99 and RSD < 8%.
• Limits of detection and quantitation were mostly < 2 µg/kg and < 10 µg/kg, respectively.
• Peak shape, retention time, and ion ratio stability were maintained over > 200 injections without source or inlet maintenance.
• The standard addition method provided accurate quantitation and corrected for recovery bias.

Benefits and practical applications

• NeverVent technology allows ion source and column exchange without venting, minimizing downtime.
• Fully automated workflow with 21 CFR Part 11 compliance supports high-throughput QA/QC testing.
• Method meets regulatory MRLs and lowers false positives through targeted SRM transitions.

Future trends and applications

• Expansion of advanced ion sources and SRM for screening additional food matrices.
• Automation of sample preparation and AI-driven data analysis for non-targeted residue screening.
• Development of ultra-inert columns and extended-range detectors to lower detection limits.
• Enterprise-level data integration and remote monitoring for harmonized regulatory workflows.

Conclusion

The TSQ 9610 with NeverVent AEI source and TRACE 1610 GC offers a robust, high-throughput solution for multi-residue pesticide analysis in edible oils, achieving sensitive detection below regulatory limits and demonstrating exceptional stability and productivity.

References

1. Karthik D and Vijayarekha K Chemometric identification of heavy metals pesticides and plasticides in edible sunflower oil Int J Food Properties 2018 21 1442–1458
2. EU Reference Laboratories for Residues of Pesticides EURL Pesticides
3. European Commission SANCO/10232/2006 Quality control procedures for pesticide residues analysis