A Validated Method for the Analysis of 142 Pesticide Residues Using Atmospheric Pressure GC Coupled with Tandem Quadrupole Mass Spectrometry

Importance of the Topic

Multi-residue pesticide analysis is critical for ensuring food safety and meeting regulatory limits. Atmospheric Pressure GC coupled with tandem quadrupole MS (APGC-MS/MS) offers improved sensitivity and selectivity compared to traditional electron impact ionization, enabling reliable detection of trace-level residues across diverse produce.

Objectives and Study Overview

This study details the development and validation of a rapid QuEChERS extraction followed by APGC-MS/MS analysis to quantify 142 pesticide residues in fruits and vegetables. Key goals included optimization of multiple reaction monitoring (MRM) transitions, evaluation of analytical performance, and demonstration of applicability to real samples.

Methodology and Instrumentation

• Sample Preparation: QuEChERS extraction (AOAC 2007.01) using DisQuE kit, followed by a tenfold dilution of the acetonitrile extract with hexane and acetone to reduce matrix load.
• Gas Chromatography: Agilent 7890A GC with DB-5MS column (30 m × 0.25 mm × 0.25 µm), helium carrier at 2 mL/min, temperature program from 70 °C to 300 °C over 30 min, pulsed splitless injection.
• Mass Spectrometry: Waters Xevo TQ-S with APGC source in positive ion mode, optimized corona and gas flows, three MRM transitions per analyte using quasi-molecular ions.
• Data Processing: TargetLynx Application Manager for quantification, ion ratio evaluation, and quality review.

Main Results and Discussion

• MRM Optimization: Soft APGC ionization preserved quasi-molecular ions, enabling selection of three sensitive transitions for each pesticide and confident confirmation at low levels.
• Linearity and Sensitivity: Calibration from 0.1 to 100 ng/mL exhibited coefficients above 0.99. Limits of detection ranged 0.01–1 µg/kg in orange, tomato, and carrot matrices.
• Matrix Effects: A tenfold extract dilution reduced interferences. Ion ratios remained within EU guideline limits (±30%, RSD <10%).
• Real Sample Analysis: Among six produce types (orange, tomato, carrot, apple, lettuce, zucchini), 43 different pesticides were identified below EU maximum residue limits.

Benefits and Practical Applications

• Enhanced sensitivity and selectivity allow sub-µg/kg detection.
• Soft ionization reduces fragmentation, improving quantitation accuracy.
• Single-platform analysis for GC- and LC-amenable pesticides streamlines laboratory operations.
• Lower matrix load prolongs instrument cleanliness and reduces maintenance.

Future Trends and Potential Applications

• Extending the scope to additional pesticides and emerging contaminants.
• High-throughput automation for large-scale monitoring.
• Application of APGC-MS/MS to complex matrices such as soils or processed foods.
• Development of standardized spectral libraries to harmonize global regulatory compliance.

Conclusion

The validated QuEChERS–APGC-MS/MS method achieves sensitive, selective, and robust quantification of 142 pesticide residues in fruits and vegetables. Performance meets regulatory requirements and supports high-throughput, single-platform pesticide monitoring.

References

• T Portolés, L Cherta, J Beltran, A Gledhill, F Hernández. Enhancing MRM Experiments in GC/MS/MS Using APGC. Waters Application Note 720004772en, 2013.
• L Cherta, T Portolés, J Beltran, E Pitarch, J G J Mol, F Hernández. Application of Gas Chromatography (Triple Quadrupole) Mass Spectrometry with Atmospheric Pressure Chemical Ionization for the Determination of Multi-Class Pesticides in Fruit and Vegetables. J Chromatogr A, 1314:224–240, 2013.