Method Validation for Simultaneous Determination of Pyriproxyfen and Fenpropathrin in Okra Matrices

Abstract

Extraction and quantification of pesticide residue from the okra matrix at or below the established maximum residue limit (MRL) is a challenging task for both analytical chemists and regulatory institutions to take corrective actions for human health and safety. to develop a simple rapid and less expensive extraction and cleanup method for simultaneous analysis of pyriproxyfen and fenpropathrin residue in okra two methods:  QuEChERS and Liquid-Liquid Extraction (LLE) were tested. Both methods produce reliable results, QuEChERS method was chosen for the present research due to its superior efficiency, low cost as well as reduced risk of exposure to solvents in comparison to Liquid-Liquid Partitioning. The residues of both pesticides were confirmed and quantified by hyphenated gas chromatography-tandem mass spectrometer (GC-MS/MS). The effect of spiking concentration, matrix effect (ME), measurement of inter- and intra-assay repeatability, reproducibility of recovery, and trueness of the results were investigated to validate the effectiveness of the method. Limit of determination (LOD) and limit of quantitation (LOQ) for both the analytes were 0.005 and 0.01 mg/kg. The % recovery of both pesticides ranged between 85.9 to 97.9 % with RSD ≤ 7.19 %. The method fulfilled all the SANTE guidelines (SANTE, 2021) and thus can be extended for routine analysis of multiclass pesticide residue in the okra matrix.