Method Validation for Determining 513 Pesticide Residues in Cucumber Using LCMS-8060NX and 308 Residues by GCMS- TQ8040NX

Importance of the Topic

Cucumber is a widely consumed raw vegetable valued for its taste and nutritional benefits. Ensuring its safety requires sensitive multi-residue pesticide analysis, as regulatory bodies like the European Union enforce strict maximum residue limits (MRLs) of 10 µg/kg for many pesticides.

Aims and Study Overview

This work validates a comprehensive analytical workflow for simultaneous determination of 513 pesticides by LC-MS/MS and 308 by GC-MS/MS in cucumber. It employs a modified QuEChERS extraction with dispersive SPE cleanup to achieve reliable quantification at or below regulatory limits.

Methodology and Instrumentation Used

• Sample Preparation: QuEChERS extraction using acetonitrile, salts, and PSA cleanup; filtration and dilution for LC analysis.
• LC-MS/MS: Shimadzu LCMS-8060NX with Nexera LC-40, using ammonium formate/formic acid gradient; ESI interface.
• GC-MS/MS: Shimadzu GCMS-TQ8040NX with SH-1ms column, splitless injection, temperature ramp up to 290 °C.
• Data Processing: LabSolutions Insight software with internal standard calibration and QA/QC flagging.

Main Results and Discussion

• Linearity: Calibration from 1–75 µg/L (LC) and 1–100 µg/L (GC) with correlation coefficients R > 0.99.
• Precision & Specificity: Repeatability (RSDr) and reproducibility (RSDR) for >98% of compounds met <20% RSD at LOQ (10 µg/kg).
• Recovery: Mean recoveries for most compounds fell within 70–120%; only a handful showed <70% but remained reproducible.
• Matrix Effects: Mitigated by matrix-matched calibration.
• Instrument Performance: Shimadzu platforms demonstrated high sensitivity and throughput, addressing early-eluting peak shape issues via co-injection.

Benefits and Practical Applications

This validated approach enables regulatory, QA/QC, and research laboratories to perform robust multi-residue pesticide screening in high-water matrices like cucumber. It reduces method development time using ready-to-use Shimadzu method packages and enhances data reliability through automated QA/QC flagging.

Future Trends and Opportunities

Advances may include integration of high-resolution mass spectrometry for non-target screening, automation of sample preparation, expansion to other produce types, and adoption of green extraction solvents. Data analytics and cloud-based platforms will further streamline multi-residue workflows.

Conclusion

The presented method meets SANTE guidelines for sensitivity, accuracy, and precision in multi-residue pesticide analysis of cucumber. Its combination of QuEChERS extraction, Shimadzu LCMS-8060NX/GCMS-TQ8040NX instrumentation, and LabSolutions Insight processing provides a reliable, high-throughput solution for ensuring produce safety.

Reference

1. EN 15662: QuEChERS method for pesticide residues by GC-MS and LC-MS(/MS).
2. SANTE 11312/2021: Analytical quality control and method validation procedures for pesticide residues in food and feed.