Determination of multiple pesticide residue in green chilli by GC-MS/MS using modifed QuEChERS as an extraction method

Importance of the Topic

Green chilli is widely consumed worldwide and can accumulate residues from organochlorine, organophosphorus and synthetic pyrethroid pesticides applied during cultivation. Reliable determination of trace-level pesticide residues in chilli is critical for food safety monitoring, regulatory compliance and protecting consumer health. The combined use of a simplified QuEChERS extraction and GC-MS/MS analysis addresses challenges in handling complex plant matrices.

Objectives and Study Overview

This study aimed to develop and validate a single-run analytical workflow for simultaneous quantification of over 50 pesticide compounds in green chilli. The goals included optimizing a modified QuEChERS extraction for efficient recovery, establishing a robust multiple reaction monitoring (MRM) method on a triple quadrupole GC-MS/MS system, and demonstrating performance in terms of sensitivity, linearity, precision and accuracy at sub-ppb levels.

Methodology and Instrumentation

The modified QuEChERS procedure was applied to 15 g homogenized chilli samples using acetonitrile extraction, MgSO4/NaCl salting, and dispersive clean-up with PSA and MgSO4. Extracts were analyzed on a Shimadzu GCMS-TQ8040 triple quadrupole GC-MS/MS system. Chromatographic separation employed an Rxi-5Sil MS column under a 36.5 min temperature program. Electron ionization with helium carrier gas was used, and Smart MRM technology from Shimadzu’s pesticide database generated optimized transitions and timing segments automatically.

Main Results and Discussion

Calibration curves for 1–91 ppb matrix-matched standards achieved correlation coefficients (r2) above 0.985. Precision assessed at 10 ppb (n=6) yielded RSD values below 14%. Recoveries from pre-extraction spikes at 10, 50 and 100 ppb ranged between 70% and 120% for all targets. No target pesticides were detected in the unspiked chilli matrix. High scan speed (20 000 u/s) and fast MRM acquisition (800 transitions/s) enabled sensitive detection at trace levels despite complex co-extractives.

Practical Benefits and Applications

• Single-run analysis of more than 50 pesticides streamlines laboratory workflows and reduces instrument time.
• Sufficient sensitivity and precision for routine monitoring of food safety and regulatory compliance.
• Applicable to diverse agricultural commodities beyond chilli, supporting quality control in food industry and research.

Future Trends and Potential Applications

Further advancement may involve integration with high-throughput autosamplers and UHPLC-MS/MS platforms for broader analyte coverage. Automation of sample preparation and data processing could enhance laboratory efficiency. Adapting the method to other challenging matrices such as spices, fruits or grains will extend its utility in global food safety monitoring programs.

Conclusion

The combined modified QuEChERS extraction and GCMS-TQ8040 Smart MRM approach delivers a robust, sensitive and high-throughput solution for multi-residue pesticide analysis in green chilli. This workflow meets stringent accuracy and precision requirements and can be adopted for routine screening across various food matrices.

References

• Sanket Chiplunkar et al. Determination of multiple pesticide residue in green chilli by GC-MS/MS using modified QuEChERS; Shimadzu Application Note PO-CON1792E, 2017.