Magnetic porous β-cyclodextrin polymer for magnetic solid-phase extraction of microcystins from environmental water samples

Microcystins (MCs) are cyclic heptapeptide toxins and tumor promoters produced by cyanobacteria, which threaten the health of humans. In this study, magnetic porous β-cyclodextrin polymer (Fe 3 O 4 @SiO 2 @P-CDP) was synthesized and characterized by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectrometry, Fourier transform infrared spectrometry, X-ray diffraction, nitrogen adsorption porosimetry and vibrating sample magnetometer. The synthesized Fe 3 O 4 @SiO 2 @P-CDP particles were then used for magnetic solid-phase extraction (MSPE) of MCs from environmental water samples, and exhibited excellent extraction performance, especially for MC-RR. Coupled with high-performance liquid chromatography with tandem mass spectrometry (HPLC–MS/MS), a simple, efficient and sensitive method for determination of trace levels of MCs was established. After the optimization of conditions, wide linear ranges (2.0–1000   pg   mL −1 ), good linearity (r 2   ≥   0.9996) and acceptable repeatability (RSD   ≤   9.4%, n   =   5) were obtained. The limits of detection (LODs, S/N   =   3) and limits of quantification (LOQs, S/N   =   10) for three MCs (MC-LR, MC-RR and MC-YR) were in the range of 1.0–2.0   pg   mL −1 and 2.0–5.0   pg   mL −1 , respectively. Typical water samples were analyzed by the developed method, and trace levels of MC-LR and MC-RR were detected. The results demonstrate that the developed method has great potential for the determination of MCs in complicated matrix.