Analysis of Multiclass Multiresidue Pesticides in Milk Using Agilent Captiva EMR—Lipid with LC/MS/MS and GC/MS/MS

Importance of the Topic

Multiresidue pesticide analysis in milk is critical for food safety due to the vulnerability of infants and children to toxic contaminants. Lipid-rich matrices like milk present significant analytical challenges, requiring robust cleanup strategies to achieve low detection limits and reliable quantitation while preventing instrument fouling.

Objectives and Overview

This study aimed to develop a streamlined workflow combining QuEChERS extraction with an advanced lipid removal cartridge (Agilent Captiva EMR—Lipid) and dual-platform detection by LC/MS/MS and GC/MS/MS. A total of 171 pesticides covering diverse chemical classes were evaluated to demonstrate the method’s applicability and performance.

Methodology and Instrumentation

Sample preparation included:

• QuEChERS extraction in 10 mL acetonitrile, followed by centrifugation
• Cleanup using a 6 mL Captiva EMR—Lipid cartridge with two successive elutions (6 mL + 1.5 mL of 80/20 ACN/H₂O)
• Water removal for GC analysis via MgSO₄ salting out

Instrumentation comprised:

• Agilent 1290 Infinity II LC system with 6470 triple quadrupole MS (LC/MS/MS)
• Agilent 8890 GC with 7010B triple quadrupole MS (GC/MS/MS)
• Standard QuEChERS and Captiva EMR—Lipid consumables

Main Results and Discussion

Comparative cleanup studies showed Captiva EMR—Lipid achieved >99 % lipid removal and minimized late-eluting interferences versus C18 SPE and conventional dSPE. Two elution steps improved average recoveries. Calibration was linear (r²>0.99) over 1–500 ng/mL. Validation across four spiking levels yielded: 98 % of pesticides within 60–120 % recovery and >95 % with ≤10 % RSD. Dual detection confirmed 42 pesticides on both platforms, highlighting complementary coverage for polar and non-polar analytes.

Benefits and Practical Applications

The workflow delivers:

• Efficient lipid removal to protect MS sources
• Sensitive quantitation down to 1 ng/mL
• High throughput with simplified pass-through cleanup
• Broad pesticide coverage in a single protocol

Suitable for regulatory compliance, QA/QC in dairy production, and routine monitoring in food safety laboratories.

Future Trends and Opportunities

Potential advancements include integration with automated sample processors, expansion to other lipid-rich foods, and coupling with high-resolution MS for non-target screening. Further miniaturization of extraction cartridges and greening of reagents may improve sustainability and throughput.

Conclusion

The combination of QuEChERS extraction and Captiva EMR—Lipid cleanup, followed by LC/MS/MS and GC/MS/MS analysis, provides a robust, reliable, and efficient method for multiclass pesticide residue analysis in milk. This workflow meets stringent recovery and precision criteria while ensuring instrument longevity.

Reference

1. Abou Donia M.A. et al. Chemical Composition of Raw Milk and the Accumulation of Pesticide Residues in Milk Products. Global Veterinaria 2010, 4(1):6.
2. GB 2763-2019 National Food Safety Standard—Maximum Residue Limits for Pesticides in Food.
3. Yang X. Analysis of Formamidine Pesticides and Metabolites in Pork and Porcine Liver Using Agilent Captiva EMR—Lipid and LC/MS/MS. Agilent Technologies, Application Note 5994-0357EN, 2019.