Method development and validation in the curry leaf matrix employing advanced mass spectrometry: quantitative...

Curry leaf is an evergreen herb with culinary, pharmaceutical, and nutraceutical applications. As pesticide residue in curry leaf has garnered significant regulatory attention in recent years, here we report a reliable method, which was validated for the determination of 265 and 225 pesticides using LC-MS/MS and GC-MS/MS, respectively. At first, the sample was comminuted after adding water (1:2). The sample preparation workflow included extraction of 10 g homogenized sample with 10 mL ethyl acetate (+1% acetic acid), cleanup by dispersive solid phase extraction (d-SPE, 50 mg PSA + 50 mg C₁₈ + 10 mg GCB + 150 mg Na₂SO₄) and the final analysis by tandem mass spectrometry. The cleanup step adeptly removed co-extractives. The method effectively reduced matrix effects and offered an LOQ of 0.01 mg kg^-1 for most compounds. The method's accuracy and precision results fulfilled the requirements of SANTE/11312/2021 guidelines at 0.01 mg kg^-1 and higher levels of fortification. The accuracy and precision results were comparable for all pesticides. The successful screening of market samples indicates its high extraction efficiency and precision for incurred residue analysis. Due to its robustness and conformity with regulatory criteria, food testing laboratories worldwide can use the method to monitor pesticide levels in curry leaves.