Determination of multiresidue pesticides in Arabian dates using LC and GC Triple Quadrupole Mass Spectrometry

Importance of the topic

Date fruits are a staple in Middle Eastern and North African diets but may carry pesticide residues due to agricultural practices. The high sugar and complex matrix of dried dates pose significant analytical challenges, making robust multi‐residue methods essential for ensuring food safety and regulatory compliance.

Objectives and study overview

This work aimed to develop and validate a sensitive, rapid LC‐MS/MS and GC‐MS/MS workflow for simultaneous quantitation of over 400 pesticide residues in commercially available dried dates. Key goals included achieving regulatory recovery and precision criteria and demonstrating applicability for routine quality control.

Methodology and instrumentation used

• Sample preparation: Modified AOAC 2007.01 QuEChERS on 15 g homogenized dates with water, extraction in 1 % acetic acid in acetonitrile, salt partitioning, and dSPE cleanup (MgSO4, PSA, C18). Final dilution: acetone for GC, 50:50 methanol/water for LC.
• Instrumentation:
  • LC-MS/MS: Shimadzu Nexera UHPLC coupled to LCMS-8060 triple quadrupole
  • GC-MS/MS: Shimadzu GCMS-TQ8050 NX with SH-Rxi™-5Sil MS column
  • Software: LabSolutions Insight Screening with Smart Pesticide Database, Automatic Adjustment of Retention Time (AART), and Synchronized Survey Scan (SSS).
• Analytical conditions:
  • LC: Shim-pack GISS C18, 2.1×100 mm, gradient from 3 % to 100 % methanol with 2 mM ammonium formate/0.01 % formic acid; 0.4 mL/min; 15 min runtime.
  • GC: 30 m×0.25 mm×0.25 µm, splitless injection, helium carrier, oven ramp 90→320 °C; 24 min runtime.
  • MRM acquisition: three transitions per analyte, 5 ms polarity switching.

Key results and discussion

• A total of 405 pesticides were monitored (205 by LC-MS/MS, 200 by GC-MS/MS).
• Calibration was linear over 2–100 ppb with r² >0.995.
• Recoveries were 70–120 % for most compounds; two pesticides fell outside SANTE/11312/2021 guidelines. Precision (RSD) was <20 %.
• Adequate separation of isomeric cyfluthrin and cypermethrin achieved; LOQ‐level RSD of 6.7 % and recovery 89.7–95 %.
• Library matching and SSS screening enhanced confidence and minimized false positives/negatives.

Benefits and practical applications of the method

• High-throughput simultaneous quantitation of >400 pesticide residues in a challenging matrix.
• Robust performance meeting regulatory QA/QC criteria for recovery and precision.
• Streamlined workflow suitable for routine food safety laboratories and screening applications.
• Advanced software features accelerate data processing and reduce the risk of misidentification.

Future trends and potential applications

• Integration with high-resolution mass spectrometry to expand analyte scope.
• Further miniaturization of QuEChERS protocols to reduce solvent use and waste.
• Implementation of AI-driven data analysis for automated spectral interpretation.
• Extension of the validated workflow to other complex food matrices such as fruits, grains, and spices.

Conclusion

The combined LC-MS/MS and GC-MS/MS MRM method developed using Shimadzu instrumentation provides sensitive, reliable, and reproducible quantitation of multi-residue pesticides in dried dates. It meets stringent regulatory standards and offers a rapid screening tool for quality control.

References

1. AOAC Official Method 2007.01: Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate.
2. European Commission SANTE/11312/2021: Analytical Quality Control and Method Validation Procedures for Pesticide Residues Analysis in Food and Feed.