Evaluation of Matrix Effect of Chilli, Cabbage and Bitter Gourd in Multiclass Multi-pesticide Residue Analysis Using Gas Chromatography Mass Spectrometry (GC-MS)

Matrix effect of twenty three (23) multi-class pesticides in three different vegetables (Bitter gourd, Chilli, Cabbage) was evaluated using modified QuEChERS [Quick (Qu), Easy (E), Cheap (Ch), Effective (E), Rugged (R) and Safe (S)] coupled with GC-MS analysis. Validation parameters (linearity, LOD, LOQ, accuracy and precision) were determined for multi-residue analysis. The Horwitz ratio was used to explain for intra-laboratory precision. The matrix effect (% ME) for each pesticide in each vegetable was assessed based on the study of slope ratio of linearity curves obtained from solvent and respective vegetable matrix. Most of the compounds had positive matrix effect and cabbage was found to be the least sensitive matrix compared to others. Recovery study was carried out fortifying pesticide mixture prepared from both pure solvent and matrix. The values of recovery percentages were satisfactory when calculated with matrix matched standard mixture (79% to 108%), with an acceptable relative standard deviation (RSD) (<20%). The results of the present study truly revealed the influence of matrix in pesticide residue estimation.

The method of estimation of multipesticide residues in three different matrices using modified QuEChERS coupled with GC-MS analysis was validated as per SANTE, 2017.

The matrix effects were truly investigated, estimated and overcome considering the positive and negative effects induced by different matrices under study.