A novel purification strategy based on functionalized melamine sponge for determining multiple pesticides in complex-matrix American Ginseng.

This study addresses the complicated pretreatment steps in pesticide residue detection of American Ginseng by introducing a simplified QuEChERS purification method. The core of this method is a novel composite material (PSA/WT@MeS) made by loading PSA and multi-walled carbon nanotubes onto a three-dimensional melamine sponge. This material effectively removes multiple interferents from complex matrices. When used in the QuEChERS workflow, it allows purification and separation of American Ginseng samples in a single step, greatly streamlining the traditional process. Combined with gas chromatography-mass spectrometry (GC-MS), 12 common pesticides in American Ginseng were measured. The method showed good linearity (R² > 0.99) for all 12 pesticides across the 1-20 µg/kg range. Detection limits ranged from 0.01 to 0.12 µg/kg, and quantification limits from 0.03 to 0.40 µg/kg. Matrix effects were kept within ±20%. At three spiked levels, average recoveries ranged from 87.8% to 109.8%, with relative standard deviations below 9.9%. This approach offers faster pretreatment and better purification. It provides a practical option for detecting pesticide residues in American Ginseng and other complex matrices.