For analysis of lower hydrocarbons up to C3, adsorption, partition chromatography and packing material with the both interactions made from adsorbent coated with stationary phase are used. With these packings, peaks of lower hydrocarbons are liable to change depending on the conditioning temperature and time, hence care must be taken to conditioning temp. and time. In spherical silica gels the Unibeads series, which has a high column efficiency, gives characteristic separation patterns depending on the pore size, and is suitable for analysis of lower hydrocarbons up to C3.
It is particularly suitable for CO2 analysis (Fig. 2). If the sample contains water, adsorptive packings are not suitable as the water produces considerable tailing. Gaskuropack 54, which is porous polymer, can however be used for the analysis of hydrocarbons up to C3 even when water is present (Fig. 3).