Exploring the effect of mesopore size reduction on the column performance of silica-based open tubular capillary columns.

摘要: Abstract We report on a modification in the hydrothermal treatment process of monolithic silica layers used porous-layered open tubular (PLOT) columns. Lowering temperature from customary 95 °C to 80 °C, size mesopores reduced by approximately about 35% 12−13.5 nm 7.5−9 nm, while specific pore volume essentially remains unaltered. This led an increase surface area (SA) 40%, quasi-independent porous layer thickness. The increased provided corresponding retention, somewhat more (48%) than expected based SA for thin columns, and less (34%) thick recipes were applied 5 μm i.d.-capillaries with length 60 cm. Efficiencies under retained conditions amounted up N = 137,000 PLOT column thickness (df) 300 nm N = 109,000 df = 550 nm. Working similar narrow pore/high columns produced new 80 °C recipe generated same number theoretical plates as wide size/low recipe. shows 80 °C-hydrothermal allows phase ratio without affecting their intrinsic mass transfer properties separation kinetics. is further corroborated fact that plate height curves former can both be well-fitted Golay-Aris equation having change intra-layer diffusion coefficient.