Solid-phase extraction based on mesoporous Fe 3 O 4 @mSiO 2 @Cu 2+ magnetic nanoparticles coupled with high performance liquid chromatography for the determination of microcystins in water samples

Abstract

Mesoporous magnetic nanoparticles of Fe3O4 @ mSiO2 @ Cu2+ were synthesized by two methods of hydrothermal synthesis and room temperature synthesis. The synthesized mesoporous Fe3O4 @ mSiO2 @ Cu2+ nanoparticles presented uniform sizes, good magnetic properties and specific selectivity. In this work, a novel magnetic solid-phase extraction (MSPE) method based on mesoporous Fe3O4 @ mSiO2 @ Cu2+ nanoparticles (NPs) coupled with high performance liquid chromatography (HPLC) was developed for the simultaneous extraction of trace amount of microcystin-LR (MC-LR) in water samples. The MSPE extraction conditions and HPLC conditions were optimized. The results showed that good linear relationship (r = 0.999 4) was obtained between peak area and mass concentration of MC-LR in the range of 0.1-15 µg/L. The limit of detection was 0.025 µg/L, and the limit of quantification was 0.082 µg/L. Furthermore, this method was used for the analysis of algal toxins in water samples with the recovery of 78%. The results indicated that Fe3O4 @ mSiO2 @ Cu2+ magnetic nanoparticles were good pretreatment alternatives for the concentration of microcystin-LR in water samples.