Sputtered alumina as a novel stationary phase for micro machined gas chromatography columns.

ABSTRACT

Silica and graphite sputtering have previously been reported as novel solid stationary phase deposition techniques for micro gas chromatography columns. As a conventional solid stationary phase in gas chromatography, compatible with sputtering yet so far unreported, alumina was evaluated in this study. Alumina sputtered semi-packed micro columns were fabricated (including an activation step) and proved able to separate a mixture of volatile alkanes (C1-C4 with isomers) in less than 1 min. Kinetic and a thermodynamic evaluation led to calculation of 4,500 theoretical plates for ethane in 1.1 m (HETPmin = 250 µm) and a Gibbs free energy for propane of 30.2 kJ mol(-1), making this stationary phase's properties very close to those observed with silica-sputtered micro columns.