Passive calibration-vapor source for a micro gas chromatograph.

Micro-electro-mechanical systems (MEMS) fabrication techniques have been used to create a calibration-vapor source for a micro gas chromatograph @CC) that employs a porous silicon (PS) reservoir and continuously generates a known quantity ofn-decane by passive diffusion through a DRTE-Si channel. Sources containing PS layers with vertical pores 3-10.6 pm (diam.) x 280 pm (depth) provided an average generation rate at 25 “C within 5% of theoretical predictions. The temperature dependence of the n-decane generation rate (lo-60 “C) was slightly higher than predicted. Results indicate that this source design is suitable for extended uGC field deployment.