There is a constant drive to speed up GC separations. Shorter analysis times provide more analyses per day, which reduces cost. One approach is to reduce column length and column diameter and columns of 0.15 mm i.d. have indeed grown in popularity. However, the majority of applications are still done with 0.25 mm and 0.32 mm columns.

SummaryA porous polymer is deposited on the inner wall of fused silica capillary columns. The retention characteristics of this porous polymer were evaluated and found to be comparable with Porapak Q. The porous polymer has a high retention volume which enables the separation of permanent gases at ambient temperatures or higher. The hydrophobic character of the porous polymer allows the injection of water containing samples without changing retention due to adsorption of water. The inertness of the porous polymer allows the elution of a range of apolar and polar compounds. The maximum temperature of the porouspolymerwasestimatedtobe250'C.With thisnewtypeof capillary column, high resolution separations are obtained in combination with short analysis times.

The determination of ppm to ppb levels of sulfur, oxygen-containing, and certain reactive hydrocarbons in bulk hydrocarbon feedstocks is important in the petroleum and petrochemical industry to minimize catalytic deactivation and improve product quality. Gas chromatography, coupled with selective or ultratrace universal detection (or both), is ideal in most cases for such analysis. However, to enhance selectivity and quantitation at the trace levels, optimized stationary phases are required. These phases are usually of the adsorbent type. This paper summarizes the performance of several state-of-the-art phases for the analyses of trace key hydrocarbons, sulfur, and oxygenated components.