ISCC 2016: Fast screening and quantification of pesticide residues in baby food using GC Orbitrap MS technology

Significance of the Topic

Pesticide residues in baby food pose serious health concerns due to infants’ vulnerability and strict regulatory limits. Rapid and reliable analytical methods are essential for ensuring food safety and regulatory compliance. Orbitrap-based GC-MS technology promises high resolution, sub-ppm mass accuracy and full-scan capabilities, offering broad screening and quantification of multiple pesticide residues in complex matrices.

Objectives and Study Overview

This study assessed the performance of a GC hybrid quadrupole-Orbitrap mass spectrometer for fast screening and quantification of 132 pesticides in baby food. Samples were spiked at 0.5–200 ng/g to evaluate sensitivity, selectivity and quantitative accuracy against conventional triple quadrupole MS.

Methodology and Instrumentation

Sample Preparation:

• Baby food (10 g) homogenized and extracted via citrate-buffered QuEChERS.
• Dispersive SPE cleanup with MgSO₄, NaCl, PSA, C18 and carbon.
• Final extracts spiked with known pesticide standards.

Instrumentation Used:

• Thermo Scientific Q Exactive GC hybrid quadrupole-Orbitrap mass spectrometer operating at 60,000 FWHM resolution.
• Thermo Scientific TraceFinder software for data acquisition and processing.
• Thermo Scientific Trace 1310 gas chromatograph with PTV cold splitless injector.
• TraceGOLD TG-5SILMS column (30 m × 0.25 mm × 0.25 μm).

Main Results and Discussion

• Sensitivity: 95% of pesticides detected at 0.5 ng/g with instrument detection limits <2 ng/g, comparable to a TSQ 8000 Evo triple quadrupole.
• Chromatographic performance: Full-scan acquisition provided 17–25 scans per peak across 4–10 min GC runs, maintaining sub-ppm mass accuracy for each scan.
• Mass accuracy and resolution: Routine 60,000 FWHM resolution eliminated isobaric interferences; average mass deviation ≤0.4 ppm (maximum 1 ppm).
• Quantitative linearity: Matrix-matched calibration showed R² > 0.99 over 0.5–200 ng/g for all analytes.
• Comparison to triple quadrupole: Orbitrap GC-MS delivered equivalent quantitative performance while offering full-scan data for non-targeted screening.

Benefits and Practical Applications

• Comprehensive screening: Full-scan high-resolution MS enables simultaneous qualitative and quantitative analysis of a broad pesticide panel.
• Regulatory compliance: Sub-ppm accuracy and robust linearity support SANCO guidelines and EU MRL requirements for infant food.
• Laboratory efficiency: Fast GC runs combined with rapid Orbitrap scanning increase throughput and reduce analytical workload.

Future Trends and Potential Applications

• Expansion to non-targeted screening: Retrospective data mining for emerging contaminants and metabolites.
• Integration with high-throughput automation for large-scale monitoring programs.
• Development of multi-residue libraries and spectral databases for high-resolution GC-MS platforms.

Conclusion

Orbitrap-based GC-MS demonstrated excellent sensitivity, selectivity and quantitative performance for pesticide residue analysis in baby food. High resolution and mass accuracy ensure confident identification and quantification at low ppb levels, meeting regulatory standards and offering a powerful alternative to triple quadrupole methods.

References

1. Commission Regulation (EU) No 396/2005 on maximum residue levels of pesticides in or on food and feed of plant and animal origin.
2. SANCO/12571/2013 Guidance document on analytical quality control and validation procedures for pesticide residues analysis in food and feed.
3. Commission Directive (EU) No 2003/13/EC amending Council Directive 96/EC on processed cereal-based and baby foods for infants.
4. Cojocariu C., Hetmanski M., Silcock P., Fussell R. J. Three-Fold Increase in Productivity for Pesticide Residue Analysis in Baby Food Using Fast Triple Quadrupole GC-MS/MS, Thermo Scientific Application Note 10432, 2015.