Analysis of Multiple Pesticide Residues in Complex Food Matrices Using High-Throughput Online Mini-SPE and GC/MS/MS

Importance of the Topic

Pesticide residues in food pose significant health risks and require efficient, reliable monitoring across diverse and complex matrices. Advances in automated sample preparation and detection methods address the growing demand for high-throughput screening and regulatory compliance in food safety laboratories.

Objectives and Study Overview

The study evaluates an end-to-end workflow integrating mini-SPE cleanup with an Agilent PAL RTC autosampler and GC/MS/MS analysis. It aims to simplify QuEChERS extract cleanup, avoid matrix-specific optimization, and enhance sample throughput while maintaining accuracy in multiresidue pesticide quantification.

Methodology and Instrumentation

Samples (apple, orange, lettuce) are extracted by QuEChERS (EN 15662) then subjected to automated mini-SPE cleanup on the Agilent PAL RTC system. Inline addition of analyte protectants and internal standards ensures consistent performance. Separation is achieved on an Agilent 7890B GC with an HP-5MS capillary column, and detection is performed on an Agilent 7000D triple quadrupole MS in MRM mode. Mini-SPE cartridges (ITSP Solutions) contain MgSO₄/PSA/C18/CarbonX. Calibration uses matrix-matched standards at 5, 10, and 50 ng/mL.

Main Results and Discussion

Compared to traditional dispersive SPE, the mini-SPE approach delivered significantly cleaner chromatograms and reduced matrix interferences. Recoveries for 133 pesticides ranged from 70 to 130 % with linear correlation coefficients >0.995. Repeatability across matrices showed RSDs below 10 % for most analytes. The fully automated cleanup and injection workflow required under 17 min per sample and enabled overlapping prep and analysis to maximize instrument utilization.

Benefits and Practical Applications

• Universal cleanup protocol for diverse food matrices without custom sorbent adjustments.
• Reduced solvent consumption and waste, supporting green chemistry.
• High sample throughput with minimal maintenance and manual intervention.
• Automated addition of internal standards and protectants for consistent quantification.

Future Trends and Applications

Continued miniaturization and integration with high-resolution MS will expand analyte coverage. Novel sorbent materials could enhance selectivity for challenging matrices. Integration with cloud data platforms and AI-driven spectral deconvolution may further streamline routine compliance testing and research workflows.

Conclusion

The combined mini-SPE and GC/MS/MS workflow on the Agilent PAL RTC platform delivers a robust, efficient solution for pesticide residue analysis in complex food matrices. It achieves high accuracy and precision, reduces solvent use and manual labor, and meets the high-throughput demands of modern food safety laboratories.

Used Instrumentation

• Agilent PAL RTC sample handling system
• Agilent 7890B gas chromatograph
• Agilent 7000D triple quadrupole mass spectrometer
• Mini-SPE cartridges (ITSP Solutions, MgSO₄/PSA/C18/CarbonX)

References

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