Miniaturization of the QuEChERS method in fruits and vegetables without cryogenic milling: approach to greener analysis of pesticide residues

Abstract

The present study explored the feasibility of miniaturizing the QuEChERS method for pesticide residue analysis in three types of fruit and vegetables comminuted under ambient conditions. Laboratory samples of > 1–2 kg of spinach, orange, and red grape containing 12 sprayed pesticides which cover broad range of physicochemical properties and up to 6 incurred pesticides were comminuted using either a universal food cutter/mixer (1-step comminution) or a combination of the cutter/mixer followed by further homogenization using an UltraTurrax (2-step comminution). Analytical test portions of different weights (15, 2, and 0.5 g) were subsequently collected, respectively. The weighed test portions were extracted with proportionally scaled-down amounts of acetonitrile and salts, and analyzed by LC-MS/MS. The results showed no problematic variability in analytical results, even for test portions as small as 0.5 g for sprayed and incurred pesticides in all commodities tested. The optimal comminution approach depended on the commodities: while 1-step comminution sufficed in most cases, certain commodities required 2-step comminution to provide sufficient homogeneity for miniaturization. The QuEChERS method can be miniaturized to a 0.5 g test portion for the commodities tested without cryogenic milling, enabling laboratories to conduct a more environmentally friendly analysis of pesticide residues.