A STUDY OF THE SURFACE MODIFICATION OF ALUMINA FOR GC

A gas chromatographic method for the separation of alkanes and alkenes present in coal mine air has been developed using modified alumina co lumns. The separation was carried out using a GC equipped with a gas s ampling valve, a FID and a surface modified alumina packed column with helium as carrier gas. An investigation was carried out into the effe cts of surface modifiers on alumina. The study examined the change in retention properties on alumina modified by alkali metal salts and the specific effects of the halide anions and metal cations. The paper de scribes the preparation of the alumina columns and the effects on sele ctivity of post heating the stationary phase. The study demonstrated t hat alumina modified with 2 % sodium chloride and post heated to 150 d egrees C was the most appropriate stationary phase.