Determination of Multiclass, Multiresidue Pesticides in Berries

Significance of the topic

Ensuring food safety in fresh produce requires accurate determination of pesticide residues at trace levels. Berries, rich in natural pigments and diverse matrices, pose analytical challenges due to interferences and matrix effects. Enhanced cleanup strategies that remove pigments while preserving analyte recovery are vital for reliable multiresidue pesticide screening by GC/MS/MS.

Objectives and Study Overview

This work aimed to develop and validate a rapid, high-throughput method for the simultaneous analysis of 108 GC-amenable pesticides in blackberry, blueberry and raspberry. The approach integrates QuEChERS EN extraction, Captiva EMR–GPF passthrough cleanup using Agilent’s advanced Carbon S sorbent, and GC/MS/MS detection. Comparative evaluation versus traditional GCB-based dispersive SPE was performed to assess recovery, reproducibility and pigment removal efficiency.

Methodology and Instrumentation

Sample preparation followed a standard QuEChERS EN protocol:

• Homogenize 10 g frozen berry sample, spike with standards and internal standards.
• Extract with 10 mL acetonitrile containing 1% acetic acid and QuEChERS EN salt packet.
• Load 3 mL crude extract onto Captiva EMR–GPF cartridge for gravity-driven passthrough cleanup.
• Dry eluent with anhydrous MgSO₄ and transfer to GC/MS/MS for analysis.

Used Instrumentation:

• Agilent 8890 GC with HP-5ms UI columns and backflushing.
• Agilent 7000D triple quadrupole GC/MS in dynamic MRM mode.
• Bond Elut QuEChERS EN extraction kit and Captiva EMR–GPF cartridges (3 mL).
• Supporting labware: Centra CL3R centrifuge, Geno/Grinder, PPM-48 manifold, ceramic homogenizers.

Main Results and Discussion

• Pigment removal exceeded 99% as confirmed by LC/UV at 450 nm and visual decolorization of extracts.
• Using Captiva EMR–GPF cleanup, over 96% of pesticides achieved 60–120% recovery with RSD < 20% at spiking levels of 10 ng/g.
• Comparative tests in blackberry showed 0% failure rate for EMR–GPF versus 4.6% failure for GCB-based cleanup, indicating improved recoveries for sensitive planar compounds.
• Method quantitation in blackberry demonstrated linearity (R² > 0.99) across 1–500 ng/g for 84 compounds; 23 analytes had elevated LLOQs due to matrix or sensitivity constraints.
• Cross-matrix verification in blueberry and raspberry yielded pass rates of > 93% and > 99% for combined recovery, precision and calibration criteria.

Benefits and Practical Applications

• Streamlined workflow eliminates multiple vortex and centrifugation steps associated with dispersive SPE.
• Selective pigment removal minimizes matrix effects and instrument contamination, extending maintenance intervals.
• Broad analyte coverage supports regulatory and QA/QC laboratories in routine monitoring of berries and other pigmented fruits.
• Passthrough cleanup is compatible with both LC/MS/MS and GC/MS/MS platforms.

Future Trends and Opportunities

• Expansion of EMR cartridge chemistries for diverse plant-origin matrices and emerging contaminants.
• Integration with automated sample preparation workstations to boost throughput and reproducibility.
• Coupling enhanced cleanup with high-resolution mass spectrometry and data-driven screening workflows.
• Development of AI-guided method optimization to tailor sorbent formulations for novel matrix challenges.

Conclusion

The combination of QuEChERS EN extraction and Captiva EMR–GPF passthrough cleanup affords a rapid, reliable and highly selective protocol for multiresidue pesticide analysis in berries by GC/MS/MS. By delivering efficient pigment removal, improved recoveries and simplified sample handling, the method meets stringent accuracy and precision criteria across multiple berry matrices and outperforms traditional GCB-based cleanup.

References

1. González-Curbelo M.Á., et al. Trends in Analytical Chemistry, 2015, 71, 169–185.
2. Varela-Martínez D.A., et al. Liquid-Phase Extraction Handbooks in Separation Science, 2020, Chp 14, 399–437.
3. Santos P.J., et al. Analysis of Multiresidue Pesticides in Salmon Using Agilent Captiva EMR–Lipid with GC/MS/MS, Agilent Technologies Application Note 5994-1717EN, 2020.
4. Zhao L. Determination of 14 Polycyclic Aromatic Hydrocarbon Compounds in Edible Oil, Agilent Technologies Application Note 5994-1483EN, 2019.
5. Zhao L., et al. Multi-Class Multiresidue Analysis of Pesticides in Edible Oil by GC-MS/MS Using Liquid-Liquid Extraction and Enhanced Matrix Removal Lipid Cartridge Cleanup, Journal of Chromatography A, 2019, 1584, 1–12.