Fast Screening and Quantification of Pesticide Residues in Baby Food Using GC Orbitrap MS Technology

Importance of the Topic

Ensuring that baby food is free of pesticide residues is critical for infant health and regulatory compliance. High‐resolution full‐scan analysis enables broad‐scope screening, improved selectivity, and retrospective data review to meet stringent safety standards.

Study Objectives and Overview

This work evaluates the Thermo Scientific Q Exactive GC hybrid quadrupole‐Orbitrap mass spectrometer for fast screening and quantification of 132 pesticides in baby food. The aims include assessing chromatographic performance, mass resolution, scan speed, sensitivity, accuracy, linearity, and comparing results against a conventional GC triple quadrupole system under SANCO guidelines.

Methodology

• Sample Preparation: Baby food samples (10 g) were extracted using the citrate‐buffered QuEChERS protocol with acetonitrile, MgSO4, NaCl, disodium hydrogen citrate sesquihydrate, and trisodium citrate dehydrate.
• Cleanup: Dispersive SPE using MgSO4, C18, PSA, and activated carbon to remove matrix interferences.
• Calibration: Extracts spiked with 132 pesticide standards at 0.5–200 ng/g; triplicate injections for each level.

Instrumental Analysis

• Gas Chromatography: Thermo Scientific TRACE 1310 GC with PTV cold splitless injection; TraceGOLD TG-5SILMS column (30 m × 0.25 mm × 0.25 µm).
• Mass Spectrometry: Q Exactive GC quadrupole-Orbitrap analyzer operating in full EI scan mode at 60,000 FWHM resolution over m/z 50–750; acquisition rates achieving >15 scans/peak.
• Data Processing: Thermo Scientific TraceFinder software for automated review, quantification, and reporting.

Main Results and Discussion

• Chromatography: Sharp peaks for early (dichlorvos at 4.46 min) and late eluters (deltamethrin at 10.33 min) with baseline separation.
• Mass Accuracy: Average deviation 0.4 ppm (all analytes <1 ppm) ensuring high confidence in identification.
• Sensitivity: 91% of pesticides exhibited instrumental detection limits (IDL) below 2 ng/g, comparable to a TSQ 8000 Evo triple quadrupole.
• Linearity: Calibration curves displayed R² >0.99 across 0.5–100 ng/g, with residuals <25%.
• Scan Speed: Full‐scan acquisition at 60,000 FWHM yielded 17 scans per 2.4 s peak while maintaining <0.4 ppm mass error per scan.

Benefits and Practical Applications

• Broad‐scope screening of hundreds of pesticides in a single run without compound‐specific acquisition methods.
• Retrospective data mining for unanticipated or newly regulated compounds.
• Elimination of isobaric interferences through high resolution, increasing result reliability in complex matrices.
• Quantitative performance matching targeted triple quadrupole methods supports routine regulatory testing.

Future Trends and Potential Applications

• Extension to other challenging food matrices such as cereals, dairy, and fruits.
• Integration of non‐targeted screening workflows to discover unknown contaminants.
• Automation of sample preparation and data analysis using AI and advanced algorithms.
• Development of miniaturized and high‐throughput platforms for large‐scale monitoring.

Conclusion

The Q Exactive GC system delivers fast, high‐resolution full‐scan analysis for comprehensive pesticide residue testing in baby food. It combines excellent chromatographic performance, sub‐ppm mass accuracy, rapid scan rates, and sensitivity comparable to triple quadrupole instruments, enabling reliable, broad‐scope screening and quantification at trace levels.

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, 16.3.2005.
2. SANCO/12571/2013 Guidance document on analytical quality control and validation procedures for pesticide residues analysis in food and feed, 19.11.2013.
3. Commission Directive (EU) No 2003/13/EC amending Directive 96/EC on processed cereal-based and baby foods, 14.2.2003.
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.