Multiresidue Pesticide Analysis with the Agilent Intuvo 9000 GC and Agilent 7000C Triple Quadrupole GC/MS

Importance of the Topic

Pesticide monitoring is essential for ensuring food safety and compliance with regulatory maximum residue levels (MRLs) established in North America, Europe, Asia, and Australia. Robust, sensitive, and high-throughput analytical workflows are required to detect multiple pesticide compounds at low concentrations across diverse food matrices.

Objectives and Study Overview

This study evaluates the performance of the Agilent Intuvo 9000 Gas Chromatograph coupled with an Agilent 7000C Triple Quadrupole Mass Spectrometer for multi-residue pesticide analysis in organic honey, jasmine rice, and loose-leaf black tea. Key goals include assessing linearity, detection limits, reproducibility, and long-term stability of the method.

Methodology

Sample preparation followed the QuEChERS protocol with specific dispersive solid-phase extraction cleanups for each matrix. Calibration standards ranged from 5 to 500 ng/mL. An inert microfluidic guard chip was employed to protect the analytical column and MS source, facilitating extended runs without performance loss.

Instrumentation Used

• Agilent Intuvo 9000 GC with mid-column backflush and HP-5ms Ultra Inert Intuvo columns (15 m × 0.25 mm, 0.25 µm)
• Multimode inlet (MMI) with ultra-inert liner and guard chip for splitless injection
• Agilent 7693B Autosampler for sandwich injections of sample, internal standard, and matrix
• Agilent 7000C Triple Quadrupole GC/MS/MS operating in dynamic MRM mode with helium as carrier gas

Main Results and Discussion

The method achieved linear calibration curves (R2 ≥ 0.990) for 97% of target pesticides across all matrices. Limits of quantification were below 7 ppb for honey and rice and below 100 ppb for tea in 94% of cases. Reproducibility was demonstrated with %RSD ≤ 30% and recovery errors ≤ 30%. The guard chip protected the system, maintaining peak shape and sensitivity for over 500 injections.

Benefits and Practical Applications

• Simultaneous multi-residue screening of hundreds of pesticides with a single workflow
• Reduced maintenance requirements through guard chip protection and backflush capability
• High throughput and robust performance suitable for regulatory and quality control laboratories

Future Trends and Potential Applications

Advances may include integration with comprehensive pesticide libraries, automated online clean-up, expansion to additional complex matrices, and coupling with high-resolution mass spectrometry for non-target screening. Miniaturized sampling and real-time monitoring are potential areas of development.

Conclusion

The Agilent Intuvo 9000 GC coupled to a 7000C Triple Quadrupole MS provides a sensitive, precise, and durable solution for multi-residue pesticide analysis in food commodities, effortlessly meeting stringent global MRL requirements.

References

1. Maximum Residue Limits Database, USDA Foreign Agriculture Service, 2016.
2. Veeneman R. Multiresidue Pesticide Analysis with the Agilent Intuvo 9000 GC and Agilent 7000 Series MS, Agilent Technologies Application Note 5991-7216EN, 2016.
3. Anastassiades M.; Lehotay S. J.; Štajnbaher D.; Schenck F. S. J. AOAC Int. 2003, 86, 412–431.
4. Lehotay S. J.; Mastovská K.; Lightfield A. R. J. AOAC Int. 2005, 88, 615–629.