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.

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 (R2 > 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. Graphical abstract Schematic presentation of design and synthesis of 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.

Ultrasound assisted dispersive solid phase extraction of triazole fungicides by using an N-heterocyclic carbene copper complex supported on ionic liquid-modified graphene oxide as a sorbent.

An ultrasound-assisted method is described for dispersive solid phase extraction of trace levels of triazole fungicides. A sorbent was prepared from an N-heterocyclic carbene copper complex that was supported on ionic liquid-modified graphene oxide. The sorbent was characterized by scanning electron microscopy, transmission electron microscopy, Raman and FT-IR spectroscopy, energy-dispersive X-ray spectroscopy and elemental mapping. The capability of sorption and extraction is mainly based on complexation with Cu (I) ions. The variables affecting extraction were optimized. Following desorption with ethanol, the fungicides were quantified by corona discharge ion mobility spectrometry. Under optimized conditions (solution pH value: 7.0; amount of sorbent: 10 mg; extraction time: 3 min; desorption agent: ethanol), the technique provides good linearity (>0.994), repeatability (RSD < 4.1%), low limits of detection (0.18 ng.mL-1), excellent preconcentration factors (468-476) and high recoveries from spiked environmental water samples (92-94%). The sorbent can be reused over five cycles without significant loss of its activity. Graphical abstract Schematic presentation of design and synthesis of the N-heterocyclic carbene copper complex supported on ionic liquid-modified graphene oxide as a sorbent for triazole fungicides and its application in ultrasound-assisted dispersive solid phase extraction with ion mobility spectrometric detection.