Multiresidue Pesticide Analysis with the Agilent Intuvo 9000 GC and Agilent 7000 Series Mass Spectrometer

Significance of the Topic

Multi-residue pesticide analysis is essential for ensuring food safety, regulatory compliance, and environmental monitoring. Governing bodies worldwide set maximum residue limits (MRLs) in diverse commodities, requiring methods that deliver accuracy and throughput across complex matrices.

Study Objectives and Overview

This study evaluated the Agilent Intuvo 9000 GC paired with a 7000 Series Triple Quadrupole MS for quantifying 21 pesticides in seven representative matrices—honey, rice, orange, black tea, olive oil, onion, and cucumber. Calibration covered 1–1000 ng/mL. A three-layer sandwich injection approach provided matrix-matched standards and streamlined the analysis.

Methodology

• Sample Preparation: QuEChERS extraction with magnesium sulfate salting out and matrix-specific dispersive SPE cleanup (EN salts, EMR-Lipid, Polish pouch).
• Matrices: High-sugar, high-lipid, high-water, acidic, dried, and pigment-rich samples.
• Calibration: Standards at 1–500 ng/mL with deuterated internal standards at 40 ng/mL; matrix blanks and analyte protectants to minimize interferences.
• Injection Workflow: Three-layer sandwich injections (matrix, protectant, standard/sample) using an Agilent 7693B autosampler.
• Maintenance: Post-60 injections replacement of septum, inlet liner, and Intuvo Guard Chip without altering retention times.

Instrumentation

• GC: Agilent Intuvo 9000 with inert flow path and Intuvo Guard Chip.
• Column: HP5-MS UI (15 m).
• MS: Agilent 7000 Series Triple Quadrupole in MRM mode (P&EP database transitions).
• Injection: Pulsed splitless at 280 °C, helium carrier gas.

Main Results and Discussion

• Linearity: R² values between 0.972 and 0.997; average 0.997 in honey and rice.
• Recovery & Precision: Average recoveries >80% at 50 ng/mL across 60 injections; RSD <10%; overall mean recovery ~100% (6.3% RSD).
• Chromatographic Stability: Overlaid chromatograms before/after 60 injections and maintenance showed consistent peak shape and retention times, obviating time locking.
• Reduced Maintenance: Guard Chip prevented matrix buildup and removed the need for column trimming, ensuring stable performance over >500 injections.

Benefits and Practical Applications

• High-throughput, multi-matrix pesticide screening with minimal downtime.
• Reliable quantitation for meeting global MRL requirements.
• Extended column life and simplified maintenance.
• Enhanced lab efficiency in QA/QC and regulatory environments.

Future Trends and Potential Applications

Future developments may include fully automated sample workflows, expanded analyte scopes, integration with high-resolution MS, and AI-driven data processing. Miniaturized, field-deployable GC-MS systems could enable on-site environmental and food safety monitoring.

Conclusion

The Agilent Intuvo 9000 GC combined with a 7000 Series Triple Quadrupole MS and Guard Chip technology offers a robust, maintenance-efficient platform for multi-residue pesticide analysis. It delivers excellent linearity, recovery, and chromatographic stability across challenging food matrices, supporting high-throughput, regulatory-compliant testing.

References

1. Maximum Residue Limits Database. United States Department of Agriculture, Foreign Agricultural Service, 2016.
2. EU Legislation on Maximum Residue Limits. European Commission, 2016.
3. Churley M., Stevens J. Reduce Cost of Pesticide Residue Analysis. Agilent Technologies Application Note 5991-6069EN, 2015.
4. Churley M. Lowering Detection Limits for Routine Pesticide Analysis Using Agilent 7000C GC/MS/MS. Application Note 5991-4131EN, 2015.
5. Zhao L. MS Analysis of Fruit and Vegetable Pesticides by GC/MS/MS Using Agilent Inert Flow Path. Application Note 5991-3234EN, 2013.