A quantitative determination of pesticide residues in chili powder using GC-MS/MS

Importance of the Topic

Chili powder is a staple spice in many cuisines and is prone to contamination by pesticide residues due to extensive pesticide application during cultivation. Monitoring these residues is vital to ensure compliance with food safety standards and to protect consumer health.

Objectives and Overview

This study presents a comprehensive analytical approach for the quantification of targeted pesticides in chili powder according to the Food Safety and Standards Authority of India (FSSAI) requirements. The method employs a combination of QuEChERS sample preparation and gas chromatography triple quadrupole mass spectrometry (GC-MS/MS) to achieve sensitive and reliable detection.

Methodology and Instrumentation Used

The sample preparation protocol includes:

• Extraction of 2 g of homogenized chili powder with acidified water followed by acetonitrile.
• Phase separation using anhydrous magnesium sulfate and sodium acetate.
• Cleanup via dispersive solid phase extraction using magnesium sulfate, PSA, C18 and graphitized carbon black to reduce matrix pigments.

Chromatographic analysis was performed on the Thermo Scientific TRACE 1310 GC coupled to the TSQ 9000 triple quadrupole MS with an ExtractaBrite ion source. A TraceGOLD TG-5MS column and a TriPlus RSH autosampler with a programmed temperature vaporizing injector in splitless mode were used. Data were acquired in SRM mode using TraceFinder software and quantified using matrix-matched calibration standards ranging from 0.005 to 0.20 mg/kg.

Main Results and Discussion

The cleanup step effectively reduced pigment contamination by more than 40%, improving instrument maintenance. Matrix effects necessitated matrix-matched calibration to correct enhancement up to 20%. The method demonstrated:

• Linearity with R2 greater than 0.99 across the calibration range.
• Limits of quantitation of 0.025 mg/kg for all target analytes.
• Recoveries between 72 and 104 with relative standard deviations below 6.2.
• Retention time precision within 0.1 minutes and ion ratio accuracy within 30% as per SANTE guidelines.

The analytical run time allowed the processing of ten samples in under eight hours.

Benefits and Practical Applications

The validated method meets FSSAI maximum residue limits and EU SANTE performance criteria, enabling routine screening of pesticide residues in chili powder. The approach offers cost savings by reducing column and liner maintenance and streamlines workflow for commercial food testing laboratories.

Future Trends and Potential Applications

Future developments may include the adaptation of this workflow to other spice matrices, further reduction of solvent usage, and increased automation to enhance throughput. Integration with high-resolution mass spectrometry or alternative extraction technologies may further improve sensitivity and selectivity.

Conclusion

A robust GC-MS/MS method has been established for the accurate quantitation of pesticide residues in chili powder. The technique satisfies regulatory requirements, delivers reliable performance at low detection limits, and supports routine food safety monitoring.

References

• Government of India Ministry of Agriculture and Farmers Welfare Directorate of Plant Protection Quarantine and Storage List of Pesticides Banned Refused Registration and Restricted in Use as of 19.03.2019
• Sivanandha Reddy C Kulavardhana Reddy S and Gopireddy Venkata Subba Reddy G Int J Eng Sci Invention 2018 2319 6726
• Arnab Goon Zareen Khan Dasharath Oulkar Raviraj Shinde Suresh Gaikwad Kaushik Banerjee J Chromatogr A 2018 1532 105 111
• European Commission Guidance on analytical quality control and method validation for pesticide residues SANTE 11813 2017
• AOAC Official Method 2007 01 Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate AOAC International 2007
• Food Safety and Standards Authority of India The Food Safety and Standards Regulations 2006