Highly Sensitive Liquid Chromatography-Mass Spectrometry Detectionof Microcystins with Molecularly Imprinted Polymer Extraction fromComplicated Aqueous Ecosystems

摘要

In the present study, a liquid chromatography-mass spectrometry (LC-MS) method has been developed and validated to monitor traces of microcystins (MCs) in lake and marine waters. The molecularly imprinted polymer (MIP) formulated with itaconic acid as the functional monomer and ethylene glycol dimethacrylate as the crosslinking monomer has been used to selectively enrich MCs from the aqueous solutions. The extraction capacity and selectivity of MIP was higher when comparison with conventionally used resin XAD and powdered activated carbon (PAC). The MIP showed an outstanding selectivity for microcystin-LR (MC-LR) in a mixture of MCs from aqueous solutions in the pH range 6-9. The LC-MS analysis of MCs after MIP extraction showed an excellent linearity in the working range (R2=0.998) with high repeatability (RSD%, <6.3) and recoveries above 90%. Interference of dissolved ions and solution pH on MCs trace quantification in the lake and marine water samples were quantified. The limits of quantification (LOQ) and lower limit of detection (LOD) for the MC-LR were 10 and 1 ng L-1, respectively, which satisfies the strictest World Health Organization standard for MC-LR in drinking water (1 ng mL-1). The proposed analytical approach is simple, efficient and comparable with the detection limit of the traditional and expensive ELISA method of MCs analysis.