Analysis of Pesticides in Celery

Importance of the topic

Pesticide contamination in fresh produce poses significant health risks and demands accurate monitoring to meet regulatory standards and protect consumer safety.
Reliable cleanup of complex matrices such as celery is essential for sensitive multi-residue analysis by LC/MS/MS.

Goals and Overview of the Study

This study implements and evaluates the Agilent Captiva Enhanced Matrix Removal General Pigmented Fresh passthrough cleanup for multiclass pesticide analysis in celery by LC/MS/MS.
The method is compared to traditional dispersive SPE with graphite carbon black to assess workflow efficiency, pigment-removal performance, analyte recovery, and precision.

Methodology and Instrumentation

Sample Preparation:

• Celery homogenized, 15 g sample extracted with 15 mL acidified acetonitrile using buffered QuEChERS salts.
• Shake and centrifugation followed by aliquot withdrawal for cleanup.

Cleanup Strategies:

• Passthrough cleanup using a three-milliliter Captiva EMR-GPF cartridge with gravity elution and positive pressure drying.
• Dispersive SPE cleanup using universal QuEChERS dSPE kit with graphite carbon black involving vortex mixing, centrifugation, and supernatant transfer.

Instrumental Conditions:

• Agilent 1290 Infinity II LC coupled to a triple quadrupole MS with Jet Stream electrospray ionization.
• Poroshell 120 EC-C18 column, column temperature 40 °C, autosampler at 10 °C, injection volume two microliter.
• Mobile phases of water and methanol with ammonium formate, ammonium fluoride, and formic acid.
• Agilent positive pressure manifold, Geno/Grinder, and standard laboratory centrifuge.

Main Results and Discussion

Passthrough cleanup reduced sample handling steps and achieved a 30–40 percent time saving compared to dispersive SPE.
Both methods provided equivalent visual pigment removal, producing clear, colorless extracts.
For 52 pesticides, Captiva EMR-GPF delivered over 90 percent average recovery and relative standard deviations below 20 percent across two quality control levels.
Increasing sample loading from two to three milliliter improved recovery of planar pesticides by reducing matrix competition on sorbent active sites.
Notably, acidic and other sensitive pesticides showed significantly higher recoveries and reproducibility with EMR-GPF cleanup, attributed to optimized carbon sorbent interactions and absence of simultaneous water removal.

Benefits and Practical Applications

• Streamlined workflow with fewer manual steps and faster throughput.
• Efficient and selective pigment removal for pigmented fresh matrices.
• Enhanced analyte recovery and precision for sensitive compounds.
• Seamless integration with standard QuEChERS extraction kits.
• Reliable quantitative analysis for regulatory and quality control laboratories.

Future Trends and Possibilities

• Application of EMR-GPF cleanup to a broader range of pigmented and high-chlorophyll commodities.
• Automation and high-throughput integration in routine pesticide screening workflows.
• Advancement of sorbent materials for expanded analyte coverage and selectivity.
• Coupling with data analytics and machine learning for improved quantitation and method optimization.

Conclusion

The Agilent Captiva EMR-GPF passthrough cleanup offers a robust and efficient alternative to traditional dispersive SPE for multi-residue pesticide analysis in celery.
It simplifies sample preparation, ensures equivalent matrix removal, and enhances recovery and reproducibility for critical analytes.

References

• Zhao L.; Wei T. Determination of Multiclass, Multiresidue Pesticides in Berries Using Captiva EMR–GPF Passthrough Cleanup by GC/MS/MS, Agilent Technologies application note 5994-4764EN, 2022.
• Zhao L. Determination of Multiclass, Multiresidue Pesticides in Bell Peppers Using Captiva EMR–GPF Passthrough Cleanup by LC/MS/MS and GC/MS/MS, Agilent Technologies application note 5994-4767EN, 2022.
• Zou A. et al. Analysis of 510 Multiple Pesticides Residues in Black Pepper Using Captiva EMR Passthrough Cleanup by LC/MS/MS, Agilent Technologies application note 5994-4768EN, 2022.