Pesticide Residues in Tobacco Using the Agilent 6470 Triple Quadrupole LC/MS/MS System

Significance of the topic

The presence of pesticide residues in tobacco poses significant health risks and regulatory challenges. Reliable multi-residue analysis supports quality control, risk assessment, and compliance with international standards.

Objectives and overview of the study

This work focused on establishing a high-throughput multiple reaction monitoring method for 40 pesticides in tobacco samples. The method leverages the Agilent 6470 Triple Quadrupole LC/MS/MS system coupled with a QuEChERS extraction protocol and matrix-matched calibration to ensure sensitivity and reproducibility.

Methodology and instrumentation

Sample preparation: 1 g of ground tobacco was extracted using an Agilent QuEChERS kit with water and acetonitrile, followed by cold precipitation, salt addition, centrifugation, and a 10-fold dilution. Matrix-matched standards were prepared by post-spiking diluted extracts across 0.05 to 100 ng/mL.
Instrumentation:

• Agilent 1290 Infinity II UHPLC
• 6470 Triple Quadrupole LC/MS/MS with Jet Stream source in positive ion mode
• RRHD Eclipse Plus C18 column (2.1 × 100 mm, 1.8 µm)
• Dynamic MRM transitions from Agilent pesticide database

Main results and discussion

The method achieved a limit of quantification of ~0.03 ng/mL and a method detection limit of 10 ng/g after 100-fold dilution. Calibration curves exhibited R² > 0.995, with recoveries between 75 % and 120 % at 10, 100, and 200 ng/g. Repeatability showed %RSD < 5 % for all analytes. Analysis of commercial tobacco samples demonstrated quantification of multiple pesticides below regulatory thresholds.

Benefits and practical applications

The streamlined QuEChERS workflow and dilution strategy minimized matrix effects and instrument contamination. High sensitivity and selectivity enable routine quality control of tobacco products and can be adapted for other complex agricultural matrices.

Future trends and potential applications

• Expansion to broader analyte panels using dynamic MRM for high-throughput screening
• Integration with high-resolution mass spectrometry for non-targeted analysis
• Automation of sample preparation and data processing
• Application of machine learning for pattern recognition and trend analysis in residue profiling

Conclusion

The validated LC/MS/MS approach provides a robust, precise, and efficient solution for multi-residue pesticide analysis in tobacco. It supports regulatory compliance and routine laboratory workflows.

References

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