Cannabis is the most frequently abused drug worldwide, and the number of cannabis users is still growing. The high lipophilicity of cannabinoids results in extremely low concentrations in wastewater, which poses difficulties and challenges for monitoring cannabinoids. In this study, a hyperbranched mixed-mode anion exchange magnetic adsorbent Fe 3 O 4 @poly(GMA/DVB-WAX) was designed based on the structural characteristics of cannabinoids, which was prepared through copolymerization of glycidyl methacrylate (GMA) and divinylbenzene (DVB) on the surface of oleic acid coated Fe 3 O 4 microspheres followed by hyperbranched modification with ethylenediamine (EDA) and 1,4-butanediol glycidyl ether (BDDGE). This magnetic solid-phase extraction (MSPE) adsorbent can selectively extract four cannabinoids, Δ 9 -tetrahydrocannabinol (THC), cannabidiol (CBD), cannabinol (CBN), 11-nor-9-carboxy-Δ 9 -tetrahydrocannabinol (THC-COOH), from wastewater through the synergistic effects of hydrophobic interactions, electrostatic interactions, π-π stacking interactions, and hydrogen bonding interactions. The entire extraction time of the adsorbent only takes five minutes and the extraction recovery rates were in the range of 69.4 %-94.0 % for four cannabinoids after the MSPE procedure optimization. An MSPE-UHPLC-MS/MS quantitative method for determination of four cannabinoids in wastewater was established and validated. The results showed that this method had a good linearity within the range of 0.5–100 ng/L (r 2 > 0.9962). The limits of detection and the limits of quantification were 0.17–0.33 ng/L and 0.50–1.00 ng/L, respectively. The proposed MSPE-UHPLC-MS/MS method based on Fe 3 O 4 @poly(GMA/DVB-WAX) is a convenient, sensitive and reliable strategy and has great application prospects in the analysis of trace cannabinoids in wastewater.
In this paper, a simple route for palladium (Pd) nanoparticles attached to the surface of hollow magnetic Fe 3 O 4 /P (GMA-DVB)-polyethyleneimine (PEI) microspheres was established. Due to the large amount of imidogen groups and tertiary amine groups presenting in the PEI, Pd 2+ ions could be anchored to the support by complexation with a polyfunctional organic ligand. Thereafter, a magnetic Pd catalyst having a high loading amount and good dispersibility was obtained by reducing Pd 2+ ions. Afterwards, the prepared catalyst was characterized by TEM, SEM, FTIR, XRD, TGA, VSM, and UV–vis in detail. Ultimately, their catalytic activity was evaluated using the reduction of 4-nitrophenol (4-NP). Research showed that the Fe 3 O 4 /P (GMA-DVB)-PEI/Pd catalyst possessed high catalytic performances for the reduction of 4-NP with a conversion rate of 98.43% within 540 s. Furthermore, the catalyst could be easily recovered and reused at least for nine successive cycles.
Shuxiang Li,Zongying Li,Feifang Zhang,Huiliang Geng,Bingcheng Yang
We describe a novel polymer-based zwitterionic stationary phase for hydrophilic interaction chromatography (HILIC). It is prepared by chemical modification of poly (glycidyl methacrylate-divinylbenzene) (GMA-DVB) by converting epoxide groups of microsphere surface to diol groups via hydrolysis, then clicking cysteine onto the microsphere with pendant double bonds of microsphere surface via “thiol-ene” click chemistry. The phase has been characterized by scanning electron micrograph, elemental analysis and zeta potential measurement. Diol and zwitterionic group (carboxylate and amine group associated with cysteine) onto the surface of GMA-DVB microspheres make them possess good hydrophilicity , as supported by effective separation towards common polar analytes. It shows good stability at alkaline solution (e.g. pH 10) and negligible bleed (e.g. only 1.7-fold blank and ~55-fold lower than a commercial silica-based polar phase tested with the minimal bleed level). Such phase exhibits specific separation selectivity to ionic analytes and simultaneous separation of anions and cations is achieved in the retention order of I − < NO 3 − < Choline < Br − < Cl − < K + < Na + .