Modified QuEChERS sample preparation method and applied for the analysis of 250 pesticide residues in Iran’s summer crops in 2021–2023 applying gas chromatography with mass spectrometry

The conventional method for monitoring and evaluating pesticide residues in a wide range is usually QuEChER and analysis by gas chromatography-mass spectrometry (GC-MS).

In this study, in order to improve the method and increase the efficiency of the method, the goal is to make modifications on the QuEChER method. The principles of the proposed method are similar to the original method, with the difference that changes were made on the step extraction and clean up step. In order to validate, parameters such as linearity, limit of quantification, limit of detection, precision, and recovery.

Linearity was obtained by injecting matrix-matched standards ranging from 0.005 to 0.750 mg kg⁻¹ of (n=3). A rage of 70-120% were recorded for the recovery of most compounds and the precision was lower than 7%. The limits of detection for pesticide residues were found in the range of 0.0025-0.005.

The results obtained from this study can be fundamental for improving the QuEChER method.