Reduced graphene oxide coated melamine sponge as cleanup absorbent for multi-residue analysis of organophosphorus pesticides in feed

Reliable detection of pesticide residues in animal feed is essential for ensuring food safety and preventing contamination throughout the food supply chain. In this study, a novel elastic adsorbent based on reduced graphene oxide-coated melamine sponge (RGO@MeS) was developed to improve matrix cleanup for the determination of 24 organophosphorus pesticides (OPs) in complex feed samples by gas chromatography–mass spectrometry (GC–MS). This innovative material enables efficient and straightforward sample preparation via simple immersion and squeezing, substantially simplifying conventional QuEChERS workflows. The method exhibited excellent linearity (R² ≥ 0.996) across a concentration range of 0.1–2 mg/kg, accompanied by minimized matrix effects that enhanced quantification accuracy. Satisfactory recoveries (74.35–126.92%) were achieved at three spiked levels (0.5, 1, and 2 mg/kg), with relative standard deviations below 15%, indicating high precision and reliability. Limits of detection (0.002–0.038 mg/kg) and quantification (0.008–0.128 mg/kg) confirmed the method's sensitivity for trace-level monitoring. Compared to conventional QuEChERS, the RGO@MeS-based approach offers superior simplicity, cost-effectiveness, and efficiency, providing an advanced sample pretreatment technique for trace-level multi-component analysis in complex matrices.