A porous composite sorbent incorporating a metal organic framework and zinc oxide in cryogel to extract carbamate pesticides

Abstract

A composite sorbent was designed and fabricated by incorporating the Materials of Institute Lavoisier (MIL-101) and zinc oxide (ZnO) into polyvinyl alcohol (PVA) cryogel. The composite sorbent was produced to extract carbamates (carbofuran, carbaryl, isoprocarb and diethofencarb) by in-syringe solid phase extraction (SPE). MIL-101 and ZnO enhanced the adsorption of the carbamates by creating π-π stacking and hydrogen bonding, while porous PVA cryogel acted as a solid support which helped to reduce backpressure in the system. The extraction of the target carbamates was optimized by varying the amount of MIL-101 and ZnO used in the sorbent fabrication, desorption conditions, sample pH, ionic strength, sample flow rate and sample volume. The extracted target carbamates were quantitatively determined using high performance liquid chromatography technique. The developed method exhibited linearity from 1.0 to 150.0 μgL−1 for all four target carbamate pesticides with a limit of detection 0.3 µg/L. The method identified carbamates in fruit juice and white wine, obtaining recoveries from 78.1 to 108.2 % and the relative standard deviation (RSD) lower than 6.3 %. The developed composite sorbent showed good accuracy, is simple to fabricate, works rapidly and can be used for 17 extraction-regeneration cycles.