Synthesis of sol–gel poly(ethylene glycol) coated foams for the microextraction of multiclass pesticides from apple juice samples

Abstract

To ensure food safety and fair-trade practices in fruit juices, a simple and efficient foam-in-syringe solid-phase extraction (FIS-SPE) method was developed and coupled with high performance liquid chromatography-diode array detection for multiclass pesticide monitoring. Sol–gel polyethylene glycol (Carbowax 20M) coated foams were fabricated, characterized, and evaluated as microextraction media for the first time. Key parameters influencing FIS-SPE performance were optimized. The method was validated for sensitivity, linearity, accuracy, precision, robustness, and selectivity. Environmental friendliness and practical applicability were assessed using appropriate metric tools. Under optimized conditions, relative recoveries ranged from 87% to 116%, with relative standard deviations below 12% for both intra-day and inter-day tests. Limits of detection were 0.8–1.5 ng mL⁻¹, and limits of quantification were 2.5–5.0 ng mL⁻¹ for a 25 mL sample volume. The enhancement factor ranged between 11 and 38, and the absolute extraction recoveries were 21–76%. As a proof of concept, the method was applied to the analysis of various commercially available fruit juice samples, demonstrating its suitability for routine pesticide monitoring in complex food matrices.