The polystyrene-divinylbenzene stationary phase hybridized with oxidized nanodiamonds for liquid chromatography

A novel polystyrene-divinylbenzene microspheres hybridized with oxidized nanodiamonds (PS-DVB-OND) was synthesized by the method of seed swelling and polymerization. The oxidized nanodiamonds (OND) were characterized by Fourier transform infrared (FTIR) spectra, X-ray phtoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), X-ray diffraction (XRD). PS-DVB-OND particles were characterized by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The result suggested that OND were successfully embedded into the polymer microspheres with the diameter of 6 ± 2 µm. Compared to polystyrene-divinylbenzene (PS-DVB) microspheres, PS-DVB-OND microspheres could tolerate higher pressure. The PS-DVB-OND microspheres were used as stationary phase of reversed-phase liquid chromatography directly and anion-exchangers after further quaternized with methylamine and 1,4-butanediol diglycidyl ether. Reversed-phase liquid chromatographic performance of PS-DVB-OND beads was investigated through separating six benzenes such as toluene, benzaldehyde, phenol, benzoic acid, 1,4-hydroquinone and methyl p-hydroxybenzoate. Inorganic anions such as F^-, Cl^-, NO₂^-, Br^-, NO₃^-, HPO₄^2- and SO₄^2-, were baseline separated on the anion exchangers of PS-DVB-OND microspheres. The result suggested that the prepared PS-DVB-OND microspheres have the potential as liquid chromatographic stationary phase under high pressure and extremely pH conditions.