Separation of light hydrocarbons by gas chromatography using serpentine as stationary phase

The application of serpentine ore (brownish colour) as a stationary phase for the separation of hydrocarbons by gassolid chromatography has been tested. Separation of methane, ethane, propane, n-butane, iso-butane and acetylene has been accomplished at room temperature (25°C). The separated components were detected with a flame ionization detector. The peaks of isobutane and n-butane were rather broad, unsymmetrical and poorly resolved at room temperature but the resolution improved and the peaks were sharper and symmetrical when the separation was carried out at a higher temperature (50°C). The variation of retention time and peak shape have been studied as a function of flow rate and temperature of separation. Light hydrocarbons (C1-C4) could be separated at 25°C on a stainless steel column (2.8 M long and 2.3 mm i.d.) packed with 60-100 mesh particles using nitrogen as carrier gas flowing at 8 mL/min. The separation of hydrocarbons on serpentine column has been successfully applied to the determination of dissolved hydrocarbon gases in transformer oil. The results of the analysis agree well with those obtained using silica gel column.