Alumina surface was modified with Fe2O3 for improved separation of alkenes and alkanes. Scanning electron microscopy (SEM)-energy dispersive X-ray analysis (EDXA) and XRD techniques were utilized to ascertain the desired modification. Various chromatographic parameters such as height equivalent to theoretical plates (HETP), number of theoretical plates (N) and tailing factor (Tf) of bare and modified alumina columns along with retention mechanism of hydrocarbon gases have been studied. The modified sorbent was applied for separation of alkenes and alkanes in a simulated mixture of coalmine gases to evaluate its qualitative performance. Modification of alumina with Fe2O3 improved the number of theoretical plates along with tailing factor for better separation and quantification that enhanced selectivity of sorbent for studied light hydrocarbons mixture. GC column prepared from the proposed material ensured the elution of unsaturated hydrocarbons after the saturated hydrocarbons of the same carbon number. (c) 2007 Elsevier B.V. All rights reserved.