Covalent organic framework-based magnetic solid phase extraction coupled with micellar electrokinetic chromatography for the analysis of trace organophosphorus pesticides in environmental water and atmospheric particulates

A magnetic covalent organic framework material (M-COF) with conjugated structure, high surface area and good chemical stability, was prepared for the adsorption of nine organophosphorus pesticides (OPPs). The extraction recovery of the M-COF for nine target OPPs were 64-91%, and the extraction dynamics was relatively fast. Based on it, a method by combining magnetic solid phase extraction (MSPE) with sweeping micellar electrokinetic chromatography (MEKC) was developed for the determination of nine OPPs in environmental water and atmospheric particle samples. The enrichment factor (EF) of MSPE-sweeping-MEKC for nine target OPPs are 1740 and 3626 times, with the limits of detection of 0.78-2.33 μg L-1. This method was used to analyze nine OPPs in environmental samples, and the recovery of nine OPPs in spiked East Lake water, Triangle Lake water, the extracts of PM2.5, PM10 and TSP were 81.0-111%, 83.6-111%, 83.1-117%, 81.7-114% and 80.2-114%, respectively. The method is sensitive, rapid and simple, and can be used for the quantification of interest OPPs in environmental samples with complex matrix.