High-efficiency solvating gas chromatography using packed capillaries

In this study, column efficiency in packed capillary column solvating gas chromatography (SGC) was investigated. Long (>3 m) fused silica capillaries with an inner diameter of 250 μm were packed with 10 and 15 μm spherical porous (300 ?) octadecyl bonded silica particles using a CO(2) slurry packing method. A 336 cm × 250 μm i.d. fused silica capillary containing 10 μm particles provided a total column efficiency of 264?000 plates (k = 0.41), corresponding to a reduced plate height of 1.27, using CO(2) as the mobile phase at a column inlet pressure of 260 atm. A minimum plate height of 12.7 μm and a maximum plate number per unit time of 813 plates/s were obtained using packed capillary SGC. Retention factors were dependent on the column inlet pressure but independent of the pressure gradient along the column. Gasoline and diesel samples were separated under SGC conditions, and the results were comparable to those obtained using typical open tubular column gas chromatography.