High-Throughput Quantification of Pesticide Residues in Complex Matrix (Chilli Powder) Using Liquid Chromatography Tandem Mass Spectrometry: Inter- and Intra-Day Validation.

Background: Chilli powder is a widely consumed spice, however during cultivation of chilli crops are often subjected to pesticide treatments to control pests and diseases. Thus, monitoring pesticide residues in such matrices is crucial for food safety and to comply with national as well as international regulations for export/import purposes. However, accurate analysis of pesticide residue in chilli powder is challenging due to its complex nature.

Objective: To develop and validate a high-throughput LC-MS/MS method for the quantification of multiclass pesticide residues in a complex chilli powder matrix.

Methods: The acetonitrile-based extraction method was optimized for chilli powder samples. The targeted analytes were separated using reverse-phase liquid chromatography and detected using tandem mass spectrometry. Validation was conducted following SANTE guideline to comply with regulatory requirements.

Results: The method with an optimised sample preparation workflow demonstrated a lower matrix effect of < 35% for the target pesticides. The LOQ was determined to be 0.005 mg/kg for 135 analytes, with recovery ranging from 70 to 110%, and intra-day and inter-day precision (%RSD) were below 15%. Analysis of market/incurred samples and measurement uncertainty further provided more confidence on the method performance.

Conclusions: The developed LC-MS/MS method provides a robust, sensitive, and high-throughput approach for the quantification of pesticide residues in complex chilli powder. Its intra- and inter-day validation confirms suitability for routine analysis in food safety laboratories.

Highlights: A high-throughput LC-MS/MS method is developed for pesticide analysis in complex chilli powder. The method was validated according to SANTE 11312/2021-v2 with excellent precision and accuracy. Suitable for routine food safety monitoring of wide range of pesticide residues in a testing laboratory.