Enhanced chromatographic performance of silicon-micromachined capillary column with clean structure and interactive plasma organic films

A clean and small dead-space-micro-column was fabricated by silicon isotropic wet etching and ultrasonic machining. The micro-column which was formed on silicon substrate was 100 /spl mu/m in width, 10 /spl mu/m in depth, and 2.0 m in length. It has a very smooth surface which was formed by isotropic wet etching using a mixture of hydrofluoric, nitric, and acetic acid. To achieve connection to the detector and injection system, a new ultrasonic machining technique was used. Stationary phase of this micro-column was made from a sputtered fluoropolymer film for enhancing separation. This micro-column demonstrates enhanced chromatographic performance for methane gas analysis.