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

Significance of the Topic

Baby food safety and pesticide residue control is critical due to infants’ vulnerability and strict regulatory maximum residue levels (MRLs). High-throughput, accurate screening methods ensure compliance and protect public health.

Study Objectives and Overview

This application note demonstrates full-scan GC-Orbitrap™ MS technology to screen, identify, and quantify 132 pesticides in baby food using fast GC separation and high-resolution accurate mass detection. The aim is to achieve broad-scope analysis with sensitivity and quantitative performance comparable to triple quadrupole GC-MS/MS under SANCO guidelines.

Methodology and Instrumentation

Sample Preparation

• Baby food extracts prepared by citrate-buffered QuEChERS
• Extracts in acetonitrile (1 g/mL) spiked with pesticides at 0.5–200 ng/g

Instrumentation

• Q Exactive GC hybrid quadrupole-Orbitrap MS
• TRACE 1310 GC with TriPlus RSH autosampler
• TraceGOLD TG-5SilMS, 15 m × 0.25 mm i.d. × 0.25 µm column

GC-MS Conditions

• Oven program: 40 °C (1.5 min) to 180 °C at 25 °C/min, then to 300 °C at 100 °C/min (3 min)
• PTV splitless injection, He carrier gas (1.2 mL/min)
• Mass range 50–500 m/z, 60,000 FWHM at m/z 200, EI mode at 70 eV
• Lockmass m/z 207.03235 for <0.5 ppm mass accuracy

Data Processing

• TraceFinder software for screening, library matching (NIST14), and quantitation

Main Results and Discussion

Chromatography and Acquisition Speed

• Efficient separation: 2.5 s peak widths, >12 points/peak at 60,000 resolution
• Clean extracted ion chromatograms for early and late eluting pesticides

Targeted Screening

• 132 pesticides identified in 10 ng/g matrix by RT (±0.1 min), mass (±2 ppm), isotopic pattern, and fragment ions

Sensitivity and Detection Limits

• 95% of pesticides detected at 0.5–1 ng/g
• IDL99 <2 ng/g for 91% of compounds, comparable to triple quadrupole GC-MS/MS

Quantification Performance

• Matrix-matched calibration (0.5–100 ng/g) with R² >0.99 and residuals <25%
• Peak area repeatability %RSD ~6% at 5–10 ng/g

Mass Accuracy and Resolution

• Sub-ppm mass errors (average 0.4 ppm) across all analytes
• 60,000 FWHM resolution eliminates isobaric interferences

Benefits and Practical Applications

Full-scan GC-Orbitrap MS enables broad-scope screening and quantification in one run, reduces false negatives, supports EU regulatory compliance, and enhances laboratory throughput.

Future Trends and Possibilities

High-resolution GC-MS may integrate automated workflows, expand non-targeted and retrospective analysis, and extend to diverse food matrices for multi-residue monitoring.

Conclusion

GC-Orbitrap MS delivers sensitive, accurate, and selective pesticide analysis in baby food with throughput and performance comparable to triple quadrupole systems, while offering unlimited screening scope.

References

1. EU Regulation 396/2005 on pesticide MRLs
2. SANCO Guidance 12571/2013 on analytical QC
3. EU Directive 2003/13/EC on baby food MRLs
4. Thermo Scientific AN10432: QuEChERS triple quadrupole GC-MS/MS
5. Thermo Scientific TN10455: High-Resolution Compound Detection