Preparation and modification of monodisperse large particle size crosslinked polystyrene microspheres and their application in high performance liquid chromatography

The traditional seed preparation method of polystyrene was improved. Firstly, low molecular weight polystyrene seed microspheres with molecular weight of about 10,000 were successfully prepared by adding copolymer inhibitor and adjusting initiator azodiisobutyronitrile. Then, the polystyrene-divinylbenzene microspheres with large particle size were successfully prepared by the method of seed swelling polymerization, using divinylbenzene as crosslinking agent. Polystyrene-divinylbenzene polymer microspheres were characterized by scanning electron microscopy and gel permeation chromatography. The results showed that the molecular weight of polystyrene seed microspheres decreased with the increase of initiator AIBN dosage. Catechol and potassium iodide could significantly reduce the molecular weight of polystyrene seed microspheres. The size of the expanded microspheres prepared from low molecular weight seeds was controllable (up to 10 μm), with uniform particle size distribution and good monodispersity. Large size polystyrene-divinylbenzene microspheres can be used as stationary phase filler for reversed-phase chromatography, and have a good effect in the purification of industrial phytol. Sulfonated-polystyrene-divinylbenzene can be used as hydrophilic chromatographic filler to separate inosine and uridine. In addition, the baseline separation of cytosine, uracil and thymine was successfully achieved by sulfonated-polystyrene-divinylbenzene column in sodium phosphate buffer/acetonitrile mobile phase.