The use of GC-MS/MS technologies for the determination of pesticides and other contaminants in food

Significance of the topic

The accurate detection of pesticide residues and other organic contaminants in food and water is critical for ensuring public health, regulatory compliance and environmental protection.

Objectives and study overview

This work examines the application of tandem mass spectrometry coupled with gas chromatography (GC-MS/MS) to address sensitivity and selectivity challenges in monitoring pesticides, dioxins and other trace analytes in complex matrices. Key case studies illustrate the use of atmospheric pressure GC (APGC), electron ionization (EI) and fast GC workflows on versatile tandem quadrupole platforms.

Methodology

Analytical workflows rely on QuEChERS extraction and cleanup for food and environmental samples, followed by GC separation and MRM-based detection. Two ionization modes are compared: classical 70 eV EI for robust fragment-based analysis, and APGC for softer ionization yielding abundant molecular or protonated ions. Fast GC columns and elevated carrier gas flows reduce cycle times and enhance late-eluting compound transmission.

Main results and discussion

• APGC-MS/MS on the Xevo TQ-XS demonstrated limits of detection down to low attogram levels for dioxins, achieving signal-to-noise ratios exceeding 5000:1 and enabling simplified sample preparation.
• Broad-scope pesticide screening of ~400 compounds at EU default MRLs (0.01 mg/kg) in celery and other produce showed >99 % detection, R²≥0.995 and RSD<10 %.
• Baby food extracts spiked at 0.001 mg/kg yielded reliable quantification and regulatory compliance at sub-MRL levels.
• Fast GC methods shortened run times without compromising sensitivity, supporting high throughput.

Benefits and practical applications of the method

• Enhanced selectivity and sensitivity through MRM reduces matrix interferences and lowers detection limits.
• APGC source flexibility allows seamless switching between GC and LC inlets on a single mass spectrometer.
• Pre-optimized MRM libraries and intuitive software (MassLynx, QuanPedia) streamline method development and compliance with EU and US EPA guidelines.
• Fast GC-MS/MS increases sample throughput in routine food safety and environmental monitoring laboratories.

Used Instrumentation

• Waters Xevo TQ-XS tandem quadrupole with APGC and EI options.
• Xevo TQ-S micro integrated with ACQUITY UPLC for combined GC and LC workflows.
• Upcoming Xevo TQ-GC EI-based GC-MS/MS system with shared software and IntelliStart tuning.

Future trends and opportunities

Integration of GC-MS/MS with advanced sample cleanup (e.g., pass-through SPE), automated high-throughput platforms and enhanced soft-ionization sources will push limits of quantification lower. Regulatory demands for infant food and water quality will drive development of sub-ppt-level methods. Hybrid approaches combining GC and LC on a single instrument will further improve laboratory efficiency.

Conclusion

GC-MS/MS remains indispensable for comprehensive contaminant analysis in food and environmental matrices. The introduction of APGC on robust tandem quadrupole platforms enhances sensitivity, selectivity and operational flexibility. Fast GC methods and unified GC/LC workflows support evolving regulatory and industrial testing requirements.

References

• Ten Dam et al. (2016) J Chromatogr. A 1477:76–90.
• Tienstra et al. (2014) Fast GC method for pesticides and PCBs in feed matrices, EPRW.
• US EPA Method 1613B for dioxin and furan analysis.