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 presence of pesticide residues in baby food poses a health risk for infants due to their low body weight and developing metabolism. Regulatory bodies in Europe enforce strict maximum residue levels (MRLs) for foods intended for infants and young children, often below the default 0.01 mg/kg. Reliable analytical methods are therefore essential to ensure compliance and protect public health.

Objectives and Study Overview

This study evaluated a comprehensive method for the determination of over 200 GC-amenable pesticides in a high-fat cottage pie baby food matrix. The method combined a modified QuEChERS extraction with an Oasis PRiME HLB pass-through SPE clean-up, followed by gas chromatography–tandem mass spectrometry (GC–MS/MS) using an atmospheric pressure gas chromatography (APGC) source. Validation was performed following SANTE guidelines at spike levels of 0.0005 and 0.001 mg/kg.

Methodology and Used Instrumentation

Sample preparation employed the QuEChERS CEN 15662 protocol modified by replacing the dSPE step with pass-through SPE using Oasis PRiME HLB to effectively remove fats, phospholipids, and pigments. Matrix-matched calibration standards ranged from 0.00025 to 0.02 mg/kg. Analytical detection was conducted on a Waters Xevo TQ-XS triple quadrupole mass spectrometer equipped with an APGC ionization source. MassLynx software controlled data acquisition and TargetLynx processed quantitation, using a 1 µL splitless injection of acetonitrile extracts.

Main Results and Discussion

The method achieved a detection capability of 0.00025 mg/kg for 209 out of 211 analytes; two compounds were affected by blank contamination or non-detection. Calibration residuals were within ±20% for 97% of analytes, with correlation coefficients (r2) above 0.99 for most compounds. Retention time and ion ratio criteria met SANTE tolerances for over 90% of pesticides. Recoveries at 0.0005 and 0.001 mg/kg were within the 70–120% acceptance range for 87% and 93% of analytes, respectively, and repeatability (RSDr) was ≤20% for 97% and 99.5% of analytes.

Benefits and Practical Applications

• Rapid and efficient removal of lipids and pigments by Oasis PRiME HLB SPE.
• High sensitivity and selectivity of APGC-MS/MS supports monitoring of infant foods at sub-µg/kg levels.
• Reduced sample preparation time compared to conventional dSPE protocols.

Future Trends and Potential Applications

Advancements may include automation of SPE clean-up, integration with high-resolution mass spectrometry for broader analyte scope, and adaptation to other complex food matrices. Emerging regulations may drive demand for multi-residue methods with even lower detection limits and faster throughput.

Conclusion

The validated GC–MS/MS method with APGC after QuEChERS extraction and Oasis PRiME HLB clean-up demonstrated high sensitivity, accuracy, and robustness for the analysis of pesticide residues in fatty baby food matrices. It is suitable for routine compliance testing against stringent MRLs for infant foods in Europe.

Used Instrumentation

• Waters Xevo TQ-XS Triple Quadrupole Mass Spectrometer
• Waters APGC (Atmospheric Pressure Gas Chromatography) Ion Source
• MassLynx MS Software
• TargetLynx Data Processing Software

Reference

1. Commission Delegated Regulation (EU) 2021/1040 on Pesticides in Food for Special Medical Purposes Developed to Satisfy the Nutritional Requirements of Infants and Young Children.
2. Commission Delegated Regulation (EU) 2021/1041 on Pesticides in 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 After QuEChERS Extraction and Clean-up.
4. Waters Applications Notebook 720005932: Oasis PRiME HLB Food Applications.
5. CEN EN 15662:2018 Foods of Plant Origin – Multimethod for Pesticide Residues Analysis Using QuEChERS.
6. Waters Application Note 720007654: Determination of Pesticide Residues in Cucumber Using GC-MS/MS with APGC After QuEChERS Clean-up.
7. SANTE/11312/2021: Guidance Document on Analytical Quality Control and Method Validation Procedures for Pesticide Residues Analysis in Food and Feed.