A micro gas chromatography column fabricated by ultrafast laser-assisted chemical etching

A novel micro gas chromatography column (μGCC) with straight-sided elliptic microchannel cross sections was prepared by ultrafast laser-assisted chemical etching inside a glass substrate. The straight-sided elliptic cross sections resulted in a uniform distribution of the flow velocity field. This uniform distribution and the use of a microchannel with a consistent composition led to a uniform stationary phase coating. Upon the separation of a test mixture of C7–C11 alkanes, highly symmetrical chromatographic peaks were obtained. The tailing factors of the chromatographic peaks ranged from 0.95 to 1.05, which satisfies the relevant provisions of Pharmacopoeia of the People's Republic of China (ChP). The test results show that the improvement of the tailing factors is mainly due to the optimization of the cross-section structure rather than the optimization of the test conditions. Notably, due to the simple preparation processes and the low cost of the glass substrate, the total manufacturing cost of this novel μGCC is low.