High-speed gas chromatography using packed capillary columns

In this article, fused silica capillaries with an inner diameter of 250 μm were packed with 5- and 10-μm spherical and irregular silica particles with pore sizes ranging from 60 to 300 Å. The columns were investigated for high-speed separation (seconds) of light hydrocarbons under gas chromatographic conditions. The effects of particle size, particle shape, and pore size were studied. As expected, a higher plate number per second (∼ 500) could be obtained using a column packed with 5-μm particles. However, longer columns could be used and shorter analysis times experienced to obtain the same resolution with 10-μm particles. Spherical particles provided a higher plate number per second than nonspherical ones. Particles with 80 Å pores were the most suitable for high-speed separations of light hydrocarbons. No loss in column efficiency was found when injecting 0.2-μL sample volumes into a 10 cm × 250-μm i.d. column packed with 10-μm particles.