Quantitative analysis of residual agricultural chemicals in food by GC-MS/MS - Quantitative analysis of pesticides in carrot extract

Significance of the Topic

Ensuring the safety of food products against residual agricultural chemicals is critical under global regulatory frameworks. The positive list system in Japan sets a uniform safety threshold of 10 ppb for individual pesticides, driving demand for analytical methods capable of accurately detecting multiple residues in complex food matrices.

Objectives and Study Overview

This study demonstrates the quantitative analysis of 150 pesticides in carrot extract using tandem mass spectrometry (GC-MS/MS) on the JMS-TQ4000GC. Key goals include achieving high sensitivity, selectivity and reproducibility in compliance with stringent safety limits.

Methodology

The AOAC 2007.01 extraction protocol was applied to 15 g of homogenized carrot. The resulting extract was spiked with a mixed standard (PL series) at concentrations of 1, 5, 10, 50 and 100 ppb. Polyethylene glycol (PEG 300) was added in the injection liner to minimize thermal degradation of analytes.

Used Instrumentation

• Gas chromatograph coupled to JMS-TQ4000GC triple-quadrupole MS/MS (JEOL)
• Column: VF-5 ms, 30 m × 0.25 mm × 0.25 µm
• Injector: splitless, 250 °C, He constant flow 1.0 mL/min
• Ionization: EI+, 70 eV, 50 µA
• Oven program: 50 °C (1 min) → 25 °C/min to 125 °C → 10 °C/min to 300 °C
• MS/MS: peak-dependent selected reaction monitoring (SRM), up to 36 000 transitions

Main Results and Discussion

SRM chromatograms clearly resolved target pesticides in both blank and spiked carrot extracts, demonstrating high matrix tolerance. Quantitative data for five replicates (n = 5) showed:

• Average recoveries between 70% and 120%
• Coefficient of variation (CV) ≤ 10% for most compounds

This illustrates the JMS-TQ4000GC’s capability for reliable multi-residue analysis with minimal interference from co-extractives.

Benefits and Practical Applications

• High sensitivity and selectivity to meet regulatory limits
• Broad compound coverage to streamline routine screening
• Robust performance in complex food matrices
• Efficient SRM scheduling for high-throughput laboratories

Future Trends and Potential Applications

Advancements may include accelerated oven ramps for faster cycle times, expanded SRM libraries for emerging contaminants, integration of automated sample preparation and adoption of machine-learning algorithms for data processing to further enhance throughput and accuracy.

Conclusion

The application of GC-MS/MS using the JMS-TQ4000GC provides a powerful solution for comprehensive pesticide residue analysis in food. Its combination of high sensitivity, selectivity and reproducibility supports compliance with stringent safety standards and meets the analytical needs of modern food-safety laboratories.

Reference

• AOAC Official Method 2007.01: Pesticide Residues in Fruits and Vegetables