Accurately Identify and Quantify Hundreds of Pesticides in a Single GC Run

Significance of the Topic

The global demand for comprehensive pesticide screening in food safety and regulatory laboratories necessitates methods capable of analyzing hundreds of residues in a single chromatographic run. Dynamic MRM (dMRM) acquisition offers enhanced sensitivity and throughput compared to traditional time-segmented MRM (TS), supporting accurate quantitation at trace levels across diverse matrices.

Objectives and Study Overview

This work evaluates the setup, performance, and throughput of TS versus dMRM strategies for the analysis of 195 pesticide targets. Both 40 min and accelerated 20 min GC-MS/MS methods were developed and applied to real food samples to compare quantitation quality, runtime efficiency, and ease of method development.

Methodology and Instrumentation

• GC-MS/MS System: Agilent 7890B gas chromatograph coupled to a 7010 triple quadrupole MS.
• Column Configuration: Two HP-5ms UI columns (15 m×0.25 mm×0.25 μm) connected via a purged ultimate union for backflushing.
• Inlet Setup: Multimode inert inlet with ultra-inert liner; helium carrier gas at constant flow.
• Oven Programs: Standard 40 min gradient and fast 20 min gradient, both with post-run backflush.
• MRM Database & Software: Agilent MassHunter Pesticide & Environmental Pollutant MRM Database, Compound List Assistant for TS, and dMRM Method Editor in MassHunter Workstation.

Main Results and Discussion

• Both TS and dMRM methods enabled the quantitation of all 195 pesticides in honey, olive oil, orange, and spinach matrices.
• dMRM scheduling reduced concurrent transitions, permitting longer dwell times and maintaining a constant MS cycle time for improved signal-to-noise.
• The 20 min fast method achieved comparable chromatographic resolution and sensitivity to the 40 min method, demonstrating high throughput capability.
• Chromatographic and quantitative performance showed consistent retention time alignment and robust peak shapes across matrices.

Benefits and Practical Applications

• Enables high-throughput multi-residue pesticide screening in a single GC run.
• Improves sensitivity and quantitative reliability via dynamic scheduling and optimized dwell times.
• Streamlines method development with graphical interfaces and a comprehensive MRM database.
• Applicable across a wide range of food matrices, meeting QA/QC and regulatory requirements.

Future Trends and Potential Applications

• Integration of predictive algorithms for retention time scheduling and transition selection.
• Extension of dMRM approaches to emerging contaminants and broader analyte classes.
• Automation of method optimization using machine learning and AI-driven workflows.
• Coupling with high-resolution MS for enhanced confirmatory analysis and non-target screening.

Conclusion

Dynamic MRM acquisition on modern GC-MS/MS platforms delivers high-throughput, sensitive, and robust multi-residue pesticide analyses. The combination of accelerated runtime options and flexible software tools supports regulatory labs and research groups in fulfilling stringent monitoring and safety goals.

Used Instrumentation

• Agilent 7890B Gas Chromatograph
• Agilent 7010 Triple Quadrupole GC/MS
• Multimode Inlet with Ultra-Inert Liner
• HP-5ms UI Columns (15 m×0.25 mm×0.25 μm)

References

• Westland J., Doherty T., Chen V. Accurately Identify and Quantify Hundreds of Pesticides in a Single GC Run. ASMS 2016, TP215.