Reduce Cost of Pesticide Residue Analysis

Significance of the topic

Ensuring the safety of food products by accurately quantifying pesticide residues is critical for protecting public health and meeting regulatory limits. Laboratories are under pressure to lower per-sample costs without sacrificing sensitivity or reliability.

Study objectives and overview

This study evaluates a miniaturized QuEChERS extraction combined with GC/MS/MS using a high-efficiency source to reduce solvent and consumable usage, lower maintenance, and achieve limits of quantitation (LOQs) below established maximum residue limits (MRLs) for common pesticides in carrot, tomato, and celery matrices.

Methodology

Samples of 2 g homogenized produce were extracted with 2 mL acetonitrile containing 1% acetic acid, using mechanical shaking and a scaled-down QuEChERS salt mixture. Dispersive SPE cleanup was performed using sorbents tailored for each matrix. Extracts were injected at 0.5 μL into an Agilent GC with backflushing and a high-efficiency source coupled to a triple quadrupole MS in MRM mode. Calibration curves covered 0.5 to 50 ng/g with 1/x weighting.

Used instrumentation

• Agilent 7890 GC with electronic pneumatic control and backflush
• Agilent 7010 Triple Quadrupole GC/MS with high-efficiency source
• Agilent 7693A Automatic Liquid Sampler
• Geno/Grinder mechanical shaker and Heraeus centrifuge

Key results and discussion

Calibration demonstrated R² ≥ 0.992 for 97% of 126 pesticides. LOQs of 1 ng/g were achieved for 86–90% of analytes, and ≤ 5 ng/g for 95–98% across the three matrices. Base-sensitive compounds captan and folpet reached LOQs of 5 ng/g in carrot and tomato and 1 ng/g in celery using deuterated internal standards. Mini-QuEChERS reduced solvent and sorbent usage, yielding cost savings of 43–48% per sample and less frequent instrument maintenance due to lower injection volumes.

Benefits and practical applications

This approach offers substantial reductions in solvent, sorbent, and labeled standard consumption while maintaining regulatory compliance. The combination of miniaturized sample prep and high-efficiency ion source enables high throughput, improved data quality at low levels, and streamlined laboratory workflows.

Future trends and potential applications

Further miniaturization, integration with automated platforms, expansion to diverse complex matrices, and adoption of advanced mass spectrometry sources can drive additional cost savings and sensitivity improvements. Incorporating more isotopically labeled standards can enhance accuracy for challenging analytes.

Conclusion

Miniaturized QuEChERS extraction coupled with a high-efficiency GC/MS/MS source achieves robust, cost-effective pesticide residue analysis with LOQs well below default MRLs. This method enhances laboratory efficiency, lowers operational costs, and ensures reliable monitoring of food safety.

References

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