Analysis of Residual Pesticides in Agricultural Products Using Nexera UC Off-Line SFE-GC/MS System

Significance of the Topic

Agricultural products must be monitored for pesticide residues to ensure food safety under Japan’s positive list system, which now covers over 800 compounds. Conventional solvent extraction methods are laborious, time-consuming and consume large volumes of organic solvents. Supercritical fluid extraction offers a faster, more efficient and environmentally friendly alternative.

Objectives and Study Overview

This study evaluates an off-line supercritical fluid extraction (SFE) workflow using the Nexera UC system coupled to GC-MS for high-throughput multi-residue pesticide analysis in brown rice. Performance metrics such as recovery, repeatability and throughput are assessed.

Methodology

• Sample Preparation: 1 g pulverized brown rice mixed with 1 g dehydrating agent; automated rack changer handles up to 48 samples consecutively.
• Extraction: Nexera UC off-line SFE with supercritical CO2 modified with methanol; static and dynamic modes at 40 °C, 15 MPa, 5 mL/min for 8 min total; trap on ODS column; elution with acetone/hexane.
• Analysis: GCMS-TQ8040 with Rxi-5Sil MS column (30 m × 0.25 mm, 0.25 μm); temperature ramp from 50 °C to 300 °C; helium carrier gas; splitless injection; MRM acquisition.

Used Instrumentation

• Nexera UC off-line SFE system
• GCMS-TQ8040 gas chromatograph–tandem mass spectrometer with Rxi-5Sil MS column

Main Results and Discussion

Spiked brown rice (100 ng/g) was analyzed for 301 pesticides. Key findings:

• Recoveries ranged from 70 % to 120 %
• Repeatability (RSD) was below 10 %
• Total automated extraction and analysis time per sample was approximately 30 minutes

These results demonstrate reliable quantitation, high reproducibility and significant time savings compared to traditional workflows.

Benefits and Practical Applications

• Simplified pretreatment with minimal manual steps and reduced solvent consumption
• Lower environmental impact through use of supercritical CO2
• Automated extraction improves throughput and minimizes human error
• Suitable for routine QA/QC screening of pesticide residues in food matrices

Future Trends and Potential Applications

Future developments may include expanding the method to other food and environmental matrices, integrating on-line SFE-GC/MS for fully automated workflows, exploring alternative modifiers or sorbents to broaden analyte scope, and coupling with high-resolution mass spectrometry for non-targeted screening.

Conclusion

The Nexera UC off-line SFE-GC/MS approach offers a rapid, robust and eco-friendly solution for multi-residue pesticide analysis in brown rice, achieving high recovery, precision and throughput while reducing operator workload and organic solvent usage.

Reference

• Miyazaki Hydro-Protect Patent No. 3645552