Determination of Pesticide Residues in Cottage Pie Baby Food Using GC-MS/MS With APGC After Extraction Using QuEChERS and Clean-up With Oasis PRiME HLB SPE

Significance of the Topic

The reliable determination of trace pesticide residues in infant and young children’s foods is critical for consumer safety and regulatory compliance under stringent European maximum residue levels (MRLs) and supports quality assurance in food production.

Objectives and Study Overview

This study demonstrates a validated workflow for quantifying over 200 GC-amenable pesticides in a cottage pie baby food matrix using a modified QuEChERS extraction followed by pass-through SPE cleanup and analysis by GC–MS/MS with atmospheric pressure gas chromatography (APGC).

Methodology and Instrumentation

Extraction and Cleanup:

• The QuEChERS CEN 15662 extraction protocol was adapted by substituting the conventional dispersive SPE with a pass-through SPE using Oasis PRiME HLB cartridges to effectively remove fats, phospholipids, and pigments.
• Matrix-matched calibration standards were prepared in the range of 0.00025–0.02 mg/kg using a commercially available multiresidue pesticide standard.

Instrumentation:

• Waters Xevo TQ-XS triple quadrupole mass spectrometer
• Atmospheric pressure gas chromatography (APGC) source
• MassLynx MS software with TargetLynx for data acquisition and processing

Main Results and Discussion

• Sensitivity: Detection limits as low as 0.00025 mg/kg were achieved for nearly all of the 211 analytes with splitless 1 µL injection, demonstrating the high sensitivity of the APGC–MS/MS system.
• Calibration performance: Over 97% of compounds exhibited calibration residuals within ±20% and correlation coefficients (r2) >0.99, meeting SANTE criteria.
• Recovery and Repeatability: At spike levels of 0.0005 and 0.001 mg/kg, 87% and 93% of analytes showed recoveries within 70–120%, while 97% and 99.5% met repeatability requirements (RSD ≤20%).
• Identification: Retention times and ion ratios were within ±0.1 min and ±30% tolerance for the majority of compounds, ensuring reliable identification.

Benefits and Practical Applications

• The Oasis PRiME HLB pass-through cleanup streamlines sample preparation by efficiently removing matrix interferences while preserving analyte recoveries.
• APGC enhances selectivity and specificity compared to conventional electron ionization, enabling the quantitation of ultra-trace pesticide levels in complex food matrices.
• The validated method supports regulatory monitoring of infant food products against European MRLs and assists industry in quality control and due diligence.

Future Trends and Applications

Advances in high-resolution mass spectrometry and automated SPE workflows may further increase throughput and broaden the scope of detectable residues. Emerging chromatography techniques and data processing algorithms will enhance multiplexed screening capabilities for comprehensive food safety surveillance.

Conclusion

The presented GC–MS/MS method with APGC detection and Oasis PRiME HLB clean-up provides a sensitive, specific, and robust approach for multiresidue pesticide analysis in infant foods. Validation against SANTE guidelines confirms its suitability for meeting stringent MRL requirements and ensuring product safety in the food industry.

References

1. Commission Delegated Regulation (EU) 2021/1040 of 16 April 2021, amending MRLs for special medical foods for infants and young children.
2. Commission Delegated Regulation (EU) 2021/1041 of 16 April 2021, amending MRLs for infant formula and follow-on formula.
3. Waters Application Brief 720007682, Determination of Pesticide Residues in Rice-Based Baby Food Using GC-MS/MS with APGC.
4. Waters Applications Notebook 720005932, Oasis PRiME HLB Food Applications.
5. European Committee for Standardisation EN 15662:2018, Multimethod for pesticide residues in plant foods using QuEChERS.
6. Waters Application Note 720007654, Determination of Pesticide Residues in Cucumber Using GC-MS/MS with APGC.
7. Document No. SANTE/11312/2021, Guidance on QC and Method Validation for Pesticide Residues Analysis in Food and Feed.