Adsorption isotherm is a term used to describe relationship between the solute concentration adsorbed onto solid surface and concentration in the mobile phase. In this thesis, attempts were made to measure reliable adsorption isotherms of diamond-packed column in order to study the surface properties of diamond particle. The diamond-packed column was first characterized by measuring the effective particle size, hold-up volume and efficiency of the column using reverse phase liquid chromatography. The measurement of the hold-up volume indicated that the column was well packed. Efficiency of the column was found to agree generally with previous works on diamonds, but showed marked variation for retained compounds. This was attributed to surface defects and it has been recommended that ways must be devised to prevent site defects when packing columns of high density.

Both retention and isotherm results confirm the presence of ionizable groups at the surface of diamond particles produced by chemical vapor deposition as reported by other researchers. Adsorption of acetone on diamond was found to be sensitive to temperature, with similar enthalpy change as those on activated carbon. - The process is exothermic on both adsorbents and low temperature adsorption on diamond appeared to be Langmuirian.