Magnetic amphiphilic adsorbent for simultaneous magnetic solid phase extraction of anesthetics from water samples

In the present work, magnetic amphiphilic adsorbent was fabricated for the simultaneous enrichment and determination of caine and benzodiazepine anesthetics from water samples for the first time. The lipophilic divinylbenzene (DVB) and hydrophilic N-vinyl-2-pyrrolidinone (NVP) were selected as co-polymerization monomers to modify the magnetic spheres with the linkage of polydopamine. The obtained core-shell magnetic amphiphilic adsorbent, Fe₃O₄@PDA@DVB-NVP, owned balanced lipophilicity and hydrophilicity and good adsorption of anesthetics at the monomer mole ratio of 1:1. Magnetic solid phase extraction based on Fe₃O₄@PDA@DVB-NVP was developed to enrich caine and benzodiazepines anesthetics from water samples. The main parameters including the quantity of magnetic adsorbent, pH value, ultrasonic adsorption time, as well as the type of eluent solvent were systematically investigated and coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Further method validation proved that the anesthetics had good linearity, sensitivity (LOQ: 0.0001 - 0.009 μg L^-1), recovery rates (61.1 - 97.2 %) and precision (RSD≤6.8 %). Compared to the reported solid phase extraction method, the present method was more sensitive, rapid and consumes less solvent, which displayed superior advantages in the determination of anesthetics from water samples.