Scan/MRM Analysis of Residual Pesticides in Foods Using GC-MS/MS (3)

Importance of the Topic

An efficient and reliable evaluation of pesticide residues in food matrices is essential for ensuring consumer safety and compliance with regulatory limits. Triple quadrupole GC-MS/MS with simultaneous scan and MRM acquisition offers comprehensive detection of both targeted and untargeted compounds in a single run.

Objectives and Study Overview

The primary goal of this study was to assess the performance of the Shimadzu GCMS-TQ8030 system in scan/MRM mode for multiresidue analysis of pesticides in paprika samples. Targeted pesticides were quantified using MRM data, while untargeted compounds were screened and semi-quantified through scan data processed in the Compound Composer Database Software Ver.2.

Methodology and Instrumentation

The following protocol was applied:

• Sample Preparation: Paprika extracts prepared by the QuEChERS method spiked at 0.01 mg/L.
• Instrumentation: GCMS-TQ8030 with Rxi-5Sil MS capillary column (30 m × 0.25 mm, 0.25 μm film).
• GC Conditions: Injection temperature 250 °C, splitless mode, oven program from 40 °C (2 min) to 310 °C at 8 °C/min.
• MS Conditions: Interface 300 °C, ion source 200 °C, acquisition in scan (m/z 50–500) and MRM modes with event times of 0.1 s for scan and 0.3 s for MRM.

Main Results and Discussion

Targeted quantification achieved strict linear calibration for compounds such as procymidone across 0.001–0.1 mg/L, with clear MRM chromatograms and reliable limits of quantitation at 0.01 mg/L. Simultaneously acquired scan spectra allowed confirmation of target analytes. Untargeted screening identified additional residues, for example quinoxyfen, by matching retention time and spectral patterns from the database and providing semi-quantitative estimates without external standards.

Benefits and Practical Applications

The combined scan/MRM approach streamlines analysis by:

• Enabling simultaneous targeted quantification and broad-spectrum screening.
• Reducing sample throughput time and resource consumption.
• Minimizing the dependency on large sets of analytical standards for unidentified residues.

Future Trends and Potential Applications

Advancements may include:

• Expansion of spectral libraries to cover emerging pesticide classes.
• Improved software algorithms for deconvolution and automated identification.
• Integration with high-resolution mass spectrometry for enhanced confidence in unknown screening.

Conclusion

The scan/MRM strategy on the GCMS-TQ8030 provides a robust platform for high-throughput, comprehensive pesticide residue analysis in food matrices, combining accurate quantification of target analytes with effective screening of untargeted compounds.

Reference

1. EURL-FV Multiresidue Method using QuEChERS followed by GC-QqQ/MS/MS and LC-QqQ/MS/MS for Fruits and Vegetables (European Reference Laboratory, 2010-M1)