Method for the determination of 326 Residual Pesticides in Rice using LCMS-8045 and GCMS-TQ8040 NX

Importance of the Topic

Rice is the most widely consumed staple food globally, especially in Asia, and pesticide application is essential to ensure adequate yields. Monitoring residual pesticides in rice is critical for consumer safety and compliance with international Maximum Residue Limits (MRLs).

Objectives and Study Overview

Shimadzu Application Development Centre developed and validated a high-throughput multiclass, multiresidue method to quantify 326 pesticides in rice using LC-MS/MS and GC-MS/MS. It covers 220 compounds by LC-MS/MS, 158 by GC-MS/MS, with 52 common analytes assessed by both techniques.

Methodology and Instrumentation

Sample preparation employed a modified QuEChERS extraction with acidified ethyl acetate and anhydrous sodium sulfate. After partitioning, aliquots were split for LC and GC analyses. Clean-up used C18 and PSA sorbents for LC-MS/MS, with additional MgSO4 for GC-MS/MS to minimize matrix effects. Chromatographic methods featured short run times (21 min for LC, 25 min for GC) and low injection volumes, enhancing throughput and column longevity. Detection relied on multiple reaction monitoring (MRM) with one target and two reference transitions per compound.

Used Instrumentation

• Shimadzu LCMS-8045 with Nexera X2 autosampler
• Shimadzu GCMS-TQ8040 NX with AOC-20i+s injector
• Columns: Shim-pack XR-ODS II (150 × 3.0 mm, 2.2 μm) and SH-I-5Sil MS (30 m × 0.25 mm, df=0.25 μm)
• LabSolutions Insight software with Smart Pesticides Database and Method Package Ver. 3

Main Results and Discussion

• Validation followed SANTE guidelines for specificity, linearity (2–20 µg/L, up to 40 µg/L), recovery, and precision
• System precision: <20 % RSD in peak areas and <1 % RSD in retention times for most analytes
• Recoveries of 70–120 % at LOQ with repeatability and reproducibility RSDs <20 %
• LOQs: 10 µg/kg for 170 compounds by LC-MS/MS and 108 by GC-MS/MS; additional compounds validated at 20 µg/kg or 40 µg/kg

Benefits and Practical Applications

• Enables rapid, sensitive screening of a broad range of pesticide residues in rice
• High throughput and reduced runtime improve laboratory productivity
• Low solvent usage and injection volume extend column life and instrument stability
• Applicable for regulatory compliance under FSSAI, EU, Japan, and APEDA standards

Future Trends and Applications

Further integration with automated sample handling and high-resolution mass spectrometry could expand analyte scope and lower detection limits. Application to other cereal grains and expanded matrices is achievable. Advances in data processing and AI-assisted identification may streamline workflow and enhance result accuracy.

Conclusion

The developed method offers a robust, efficient, and sensitive solution for multiclass pesticide residue analysis in rice, meeting international regulatory requirements and supporting high-throughput laboratory operations.

Reference

1. Anastassiades M, Lehotay SJ, Štajnbaher D, Schenck FJ. Fast and easy multiresidue method employing acetonitrile extraction/partitioning and dispersive solid-phase extraction for the determination of pesticide residues in produce. J AOAC Int 2003;86:412–431.
2. European Commission. SANTE/12682/2019 Guidance document on analytical quality control and method validation procedures for pesticide residues in food and feed.