Hydrocarbon type and other compositional parameters of microcrystalline wax (MCW) and its. bauxite percolate, i.e., FDA (Food and Drug Administration, USA) grade MCW is studied in relation to its chemical composition. Mass spectrometric technique has been shown to be applicable to monitor the changes in composition of such products of higher carbon range. The study also confirms similar adsorption behaviour of monoaromatics with long alkyl chain, and condensed ring naphthenes on bauxite column.