Examining Maximum Residue Levels for Multiresidue Pesticides in Jasmine Rice

Significance of the topic

The monitoring of pesticide residues in food commodities such as jasmine rice is critical to ensure consumer safety, regulatory compliance, and environmental protection. As pesticide use continues to rise, analytical methods must offer low limits of quantitation, broad multiresidue capability, and robust mitigation of complex matrix interferences.

Objectives and overview of the study/article

This application note evaluates a complete multiresidue pesticide workflow for jasmine rice using the Agilent Intuvo 9000 gas chromatograph coupled to a 7000C triple quadrupole GC/MS system. Key goals include demonstrating linear calibration over regulatory ranges, achieving limits of quantitation below maximum residue level (MRL) thresholds, and verifying method precision and accuracy for both US and EU MRL targets.

Methodology and instrumentation

Sample Preparation:

• Homogenize 3 g of jasmine rice and add water and acetonitrile.
• Perform QuEChERS extraction with EN salts, followed by dispersive SPE cleanup optimized for high-starch matrices.
• Centrifuge and transfer cleaned extract to vials for analysis.

Instrumentation Used:

• Agilent Intuvo 9000 GC with inert mid-column backflush configuration and Guard Chip protection.
• Agilent 7693B autosampler with a pulsed splitless multimode inlet (MMI) and 15 m × 0.25 mm HP-5ms Ultra Inert Intuvo columns.
• Agilent 7000C triple quadrupole GC/MS in dynamic MRM (dMRM) mode for selective quantitation.

GC/MS/MS Method Highlights:

• Carrier gas: helium; inlet pressure ~2 psi; oven ramp from 60 °C to 310 °C.
• MRM transitions optimized via Agilent Pesticides MRM Database with dwell times ≥10 ms.
• Instrument cleaning via mid-column backflush and solvent washes between injections to reduce carryover.

Main results and discussion

Calibration and Sensitivity:

• Excellent linearity (R² ≥ 0.995) over 5–500 ppb for target analytes.
• Instrument detection limits (MDLs) ranged from 0.03 to 1.84 ppb; instrument LOQs below 4 ppb.

Regulatory Compliance:

• All US MRLs (10–500 ppb) and EU default (10–50 ppb) values were met with significant margin.
• Representative compounds (e.g., aldrin, lindane, DDT) demonstrated MDLs <1 ppb and LOQs <7 ppb.

Precision and Accuracy:

• Repeatability RSD ≤ 30 % for all analytes.
• Recovery errors consistently under 30 %, meeting typical validation criteria.

Matrix Interference Control:

• Selective dSPE cleanup and MRM detection minimized coelution and signal suppression in the high-starch rice matrix.

Benefits and practical applications

The described workflow offers a streamlined, cost-effective solution for routine multiresidue pesticide screening in rice and similar commodities. Key advantages include:

• Reduced maintenance through Guard Chip protection and automated backflush.
• High throughput enabled by simplified QuEChERS sample prep and rapid GC ramps.
• Enhanced selectivity and sensitivity for low-level quantitation using triple quadrupole MS/MS.

This method supports regulatory laboratories, food quality control, and agricultural testing to efficiently verify compliance with international MRL standards.

Future trends and potential applications

Looking ahead, integration of automated sample-prep platforms, further miniaturization of extraction protocols, and adoption of advanced data analytics (including AI-driven automated peak detection) will enhance throughput and robustness. Expansion of the workflow to other food matrices (fruits, vegetables, oils) and incorporation of high-resolution MS for non-target screening are promising directions.

Conclusion

The Agilent Intuvo 9000 GC with the 7000C triple quadrupole MS and a dedicated Pesticides Workflow Kit delivers a fully validated multiresidue pesticide method for jasmine rice. Achieving excellent linearity, low detection limits, and reliable precision, this configuration meets both US and EU MRL requirements and offers a user-friendly, high-performance solution for routine food safety analysis.

References

1. United States Department of Agriculture, Maximum Residue Limits Database. Retrieved July 7, 2016.
2. Churley, M. Lowering Detection Limits for Routine Analysis of Pesticides Residues in Foods Using the Agilent 7000C Triple Quadrupole GC/MS. Agilent Technologies Application Note 5991-4131EN, 2015.
3. Veeneman, R. Multiresidue Pesticide Analysis with the Agilent Intuvo 9000 GC and Agilent 7000 Series Mass Spectrometer. Agilent Technologies Application Note 5991-7216EN, 2016.
4. Churley, M. Reduce Cost of Pesticide Residue Analysis. Agilent Technologies Application Note 5991-6069EN, 2015.