Preparation and Characterization of Nano-Fe3O4 and Its Application for C18-Functionalized Magnetic Nanomaterials Used as Chromatographic Packing Materials

A new type of magnetic nanomaterial with Fe3O4as the core and organic polymer as the shell was synthesized by seed emulsion polymerization. This material not only overcomes the problem of insufficient mechanical strength of the organic polymer, it also solves the problem that Fe3O4is prone to oxidation and agglomeration. In order to make the particle size of Fe3O4meet the requirement of the seed, the solvothermal method was used to prepare Fe3O4. The effects of the reaction time, amount of solvent, pH value, and polyethylene glycol (PEG) on the particle size of Fe3O4were investigated. In addition, in order to accelerate the reaction rate, the feasibility of preparing Fe3O4by microwave was studied. The results showed that under the optimum conditions, the particle size of Fe3O4could reach 400 nm and had good magnetic properties. After three stages of oleic acid coating, seed emulsion polymerization, and C18 modification, the obtained C18-functionalized magnetic nanomaterials were used for the preparation of the chromatographic column. Under optimal conditions, stepwise elution significantly shortened the elution time of sulfamethyldiazine, sulfamethazine, sulfamethoxypyridazine, and sulfamethoxazole while still achieving a baseline separation.Keywords:solvothermal method;chromatographic packing materials;magnetic Fe3O4particles;C18-functionalized magnetic nanomaterials