Preparation and Characteristics of a Novel Sorptive Extraction Stir Bar Based on Cd-Imprinted Polymer Monoliths

A novel monolithic stir-bar for Cd(II) sorption extraction was prepared by ion-imprinting technology and in situ stepwise polymerization of epoxy resin (EP). The condensation product of diethylenetriamine and thiourea (DETATUC) was used as a curing agent, with Cd ions as template ions and polyethylene glycol 1540 as a porogenic agent. The main parameters of the stir-bar sorption extraction-EP-DETATUC material for the extraction and desorption of Cd(II) in aqueous solution were investigated, and inductively coupled plasma-atomic emission spectrometry was performed. The results showed that the monolithic material possessed good permeability and reusability. The maximum adsorption capacity was 136.58 μmol g(-1) at pH 6.0. The optimized conditions were the following: stirring rate at 300 rpm, adsorption time at 40 min, elution media at 0.25 mol L(-1) EDTA, and elution time at 20 min. The accuracy of the method was assessed by spiking two water samples and one plant sewage sample with Cd at two concentration levels. Recoveries of 96-102% were obtained.