Regularities of retention of benzoic acids on microdispersed detonation nanodiamonds in water-methanol mobile phases

The dependences of the retention of benzoic acids on microdispersed sintered detonation nanodiamond (MSDN) on the concentration of the organic solvent in the eluent and the temperature of the chromatographic column under conditions of high-performance liquid chromatography (HPLC) are investigated. It is found that in the investigated range of methanol concentrations, the acids are retained by different mechanisms: at methanol contents of the eluent lower than 85%, retention decreases with increasing methanol concentration and increases at higher concentrations of the organic solvent. It is shown that retention of benzoic acids on MSDN under these conditions depends on the dissociation constant of the investigated substances. A comparison is made between the properties of MSDN and analogous properties of porous graphitic carbon.