Three-Fold Increase in Productivity for Pesticide Residue Analysis in Baby Food Using Fast Triple Quadrupole GC-MS/MS

Significance of the topic

Ensuring the safety of baby food with regard to pesticide residues is crucial because infants are particularly sensitive to trace contaminants. Regulatory bodies set strict maximum residue limits (MRLs) and high-throughput laboratories require rapid, reliable methods to maintain consumer safety without compromising productivity.

Objectives and Study Overview

This study evaluates a fast, robust workflow for multi-residue pesticide analysis in baby food using the Thermo Scientific TSQ 8000 Evo triple quadrupole GC-MS/MS system. The goal was to accelerate sample throughput by direct injection of QuEChERS acetonitrile extracts and by implementing rapid temperature ramps in GC while preserving sensitivity and data integrity.

Methodology and Instrumentation

Used Instrumentation

• Thermo Scientific TRACE 1310 GC coupled to TSQ 8000 Evo triple quadrupole MS/MS (EI positive mode).
• TriPlus RSH autosampler and TRACEGOLD TG-5SilMS capillary column (15 m × 0.25 mm I.D., 0.25 µm film).
• Timed selected reaction monitoring (t-SRM) with 264 transitions, dwell times 1–52 ms.
• Data acquisition and processing using Thermo Scientific TraceFinder 3.2.

Sample Preparation and Chromatography

• Citrate-buffered QuEChERS extraction: 10 g homogenized baby food with 10 mL acetonitrile and salting agents (MgSO₄, NaCl, citrate salts).
• Dispersive SPE cleanup with MgSO₄, C18, PSA, carbon.
• Direct injection of 1 µL extract (no solvent exchange) in splitless mode at 240 °C.
• Oven program: 60 °C (1 min) → 180 °C at 50 °C/min → 320 °C at 35 °C/min (4 min hold).
• Carrier gas: helium at 1.2 mL/min.

Mass Spectrometry Parameters and Data Processing

• Electron ionization at 70 eV; ion source 320 °C; transfer line 280 °C.
• Q1/Q3 resolution 0.7 Da; collision gas argon at 60 psi.
• For each pesticide two SRM transitions: one for quantitation and one for confirmation.
• Timed SRM scheduling ensured ≥12 data points per peak.

Main Results and Discussion

A GC run time of ~11 min (SRM) replaced the conventional ~42 min full-scan method, yielding a three-fold increase in sample throughput without loss of data quality. Sensitivity allowed detection of 97% of 132 target pesticides at 0.5–1.0 ng/g, with linear calibration (R² > 0.99) and residuals <20% across 0.5–100 ng/g (or 1–200 ng/g). Instrument detection limits ranged from 0.2 to 3.7 ng/g; peak area repeatability averaged 7.3 %RSD. Simultaneous full-scan and SRM acquisition enabled non-target screening, identifying metolachlor in baby food via library matching (95% match probability).

Benefits and Practical Applications

• Tripled laboratory throughput for high-volume pesticide monitoring.
• Elimination of solvent exchange reduces preparation time and costs.
• High sensitivity and reproducibility at sub-ng/g levels meet stringent regulatory standards.
• Combined targeted quantitation and non-target screening in a single analysis enhances contaminant surveillance.

Future Trends and Applications

Further advancements in fast GC-MS/MS instrumentation and real-time data processing will continue to shorten analysis times and broaden analyte scope. Integration with machine learning for automated library searches and cloud-based laboratory information management systems (LIMS) promises enhanced response capabilities for emerging contaminants in food safety.

Conclusion

The fast GC-MS/MS workflow using the Thermo Scientific TSQ 8000 Evo system offers a robust, high-throughput solution for pesticide residue analysis in baby food. It delivers rapid run times, excellent sensitivity, and comprehensive monitoring, supporting both regulatory compliance and operational efficiency.

References

• Commission Regulation (EU) No 396/2005 on maximum residue levels of pesticides in or on food and feed.
• SANCO/12571/2013 Guidance document on analytical quality control and validation procedures for pesticide residues analysis.
• EN 15662:2008 Foods of plant origin – Determination of pesticide residues using QuEChERS and GC-MS/LC-MS/MS.