A mesoporous nanosorbent composed of silica, graphene, and palladium (II) for ultrasound-assisted dispersive solid-phase extraction of organophosphorus pesticides prior to their quantitation by ion mobility spectrometry

摘要

A new ultrasonic-assisted dispersive solid-phase extraction method using mesoporous nanosorbent composed of silica, graphene, and palladium (II) (M S/G@-SH@Pd (II)), coupled with corona discharge ion mobility spectrometry, was developed for trace determination of organophosphorus pesticides. Initially, the M S/G@-SH@Pd (II) nanosorbent was synthesized and characterized. Then, the nanosorbent was used for the sorption and extraction of organophosphorus pesticides. Under the optimized conditions (pH = 7.0, 15 mg of sorbent, 3 min extraction time, ethanol as desorption agent, 3 min centrifuge time), the proposed technique provided good linearity (R-2 > 0.994), repeatability (RSD < 4.6%), low limits of detection (0.15-0.30 ng mL(-1)), excellent preconcentration factor (PF = 472-478), and high recoveries (93-94%). The method was applied to the determination of organophosphorus pesticides in real water samples. The sorbent was reused in 5 cycles without any considerable loss of activity.