A phenylenediamine-based carbon dot-modified silica stationary phase for hydrophilic interaction chromatography

Red emitting carbon dots derived from p-phenylenediamine (PPDCDs) were successfully prepared and grafted onto the surface of silica spheres, which served as a new stationary phase (Sil-PPDCDs) for liquid chromatography with excellent hydrophilic selectivity. Various hydrophilic analytes including nucleosides and bases, amino acids, saccharides and ginsenosides can be well separated on this stationary phase. Compared with the precursor-modified silica, i.e. p-phenylenediamine functionalized silica stationary phase (Sil-PPD), Sil-PPDCDs possessed enhanced selectivity for the separation of tested polar compounds. Moreover, compared with two commercially available hydrophilic columns, the selective behavior of the stationary phase was also considerable. The successful application of the Sil-PPDCDs stationary phase again indicated the great potential of carbon dots as a new modifier of the stationary phase in high performance liquid chromatography, and this kind of new stationary phase is very promising to be used for the separation of hydrophilic compounds in biochemical and pharmaceutical analysis.