Synthesis of divinylbenzene polymer/Fe3O4 hybrid monolithic column for enrichment and online thermal desorption of methylmercury in real samples

A novel method of divinylbenzene polymer (DVB)/Fe3O4 hybrid monolithic column solid phase extraction and on line thermal desorption was developed to analyze methylmercury (MeHg) in water and fish samples. The monolithic column was prepared by in situ polymerization in silica tube and its heating characteristic was studied in detail. Special accent was put on the study of parameters influencing adsorption and desorption of MeHg, such as pH, flow rate of sample solution, temperature of desorption and flow rate of carrier. Under optimum conditions, the detection limit and relative standard deviation of MeHg were 0.09ngL−1 and 2.6% (10ngL−1, N=11), respectively. Recoveries of MeHg were never less than 96%. Standard reference material GBW10029 was analyzed for validation of the methodology. This method was successfully applied to the determination of MeHg in water and fish samples. [Display omitted] •We fabricate a novel DVB/Fe3O4 hybrid monolith by in situ polymerization.•MeHg in sample solution is enriched on the monolith.•Electromagnetic induction heating is used for online thermal desorption.•Limit of detection for MeHg is as low as 0.09ngL−1.