Simultaneous determination of residual agricultural chemicals in food by GC-MS/MS

Significance of the Topic

Monitoring pesticide residues in food is critical for ensuring public health and regulatory compliance. The increasing number of compounds subject to maximum residue limits demands analytical methods with high sensitivity, selectivity, and throughput.

Objectives and Study Overview

The primary goal of this work was to assess the performance of the JMS-TQ4000GC GC-MS/MS system for simultaneous quantification of 150 agricultural chemicals in food matrices. Key objectives included establishing sensitivity at 1 ppb and evaluating linearity over a 1–100 ppb range.

Methodology and Instrumentation

• Sample Preparation: A standard pesticide mixture (FUJIFILM Wako PL series) containing eight representative compounds was diluted to 1, 5, 10, 50, and 100 ppb. PEG 300 was added to prevent thermal degradation in the injection liner.
• Instrument: JEOL JMS-TQ4000GC GC-MS/MS.
• Ionization: Electron impact (EI+) at 70 eV, 50 μA.
• GC Conditions: VF-5ms column (30 m × 0.25 mm, 0.25 μm); oven program 50 °C (1 min) → 25 °C/min to 125 °C → 10 °C/min to 300 °C; inlet temp 250 °C; splitless injection of 2 μL; He constant flow at 1.0 mL/min.
• MS/MS Mode: Peak-dependent selected reaction monitoring (SRM) with up to 36,000 transitions using an ion-storage/ejection collision cell.

Results and Discussion

The JMS-TQ4000GC delivered excellent linearity for all 150 pesticides, with correlation coefficients R ≥ 0.995 across the 1–100 ppb range. Many compounds were reliably detected at 1 ppb—one-tenth of the regulatory threshold of 10 ppb under Japan’s positive list system. Representative SRM chromatograms and calibration curves for atrazine, triallate, phorate, and chlorpropham confirmed high signal-to-noise and reproducible retention times.

Benefits and Practical Applications

• Comprehensive Multi-Residue Analysis: Enables simultaneous quantification of dozens to hundreds of pesticides in a single run.
• High Sensitivity: Detection down to 1 ppb supports compliance with stringent regulatory limits worldwide.
• Improved Selectivity: SRM mode minimizes interferences, enhancing accuracy in complex food matrices.
• High Throughput: Automated transition management and rapid temperature programming shorten analysis time.

Future Trends and Opportunities

Advances may include expanded compound libraries, integration with automated sample preparation platforms, and application of machine‐learning algorithms for peak identification and quantitation. Miniaturized GC-MS/MS systems and ambient ionization techniques may further streamline routine monitoring in field or point-of-release settings.

Conclusion

The JMS-TQ4000GC GC-MS/MS system demonstrates robust sensitivity, excellent linearity, and high selectivity for multi-residue pesticide analysis in food. Its capabilities meet current regulatory requirements and offer a versatile platform for future expansions in food safety testing.