A chemometric cleanup using multivariate curve resolution in liquid chromatography: Quantification of pesticide residues in vegetables

Both extraction and chemical cleanup are steps performed when the official AOAC 2007.01 QuEChERS method is used. The chemical cleanup step is required because many co-extractives may still be present after the whole samples extraction; however, it may reduce recovery of certain analytes due to non-selectivity of this step. In addition, unexpected constituents may still interfere with the analysis even when chemical cleanup is carried out, impairing univariate quantification. A chemometric cleanup using MCR-ALS is proposed as an alternative to the QuEChERS chemical cleanup. The performance of the proposed approach was demonstrated through quantification of seven pesticide residues (Carbendazim, Thiabendazole, Fuberidazole, Carbofuran, Carbaryl, 1-naphthol, and Flutriafol) in four non-spiked vegetable samples using HPLC-DAD. With the proposed strategy, it was possible to perform a reliable quantification despite the presence of co-eluted constituents (analytes and interferents), peak shift, band shape changes and avoiding the chemical cleanup with low analyte losses and LOD.