Micro flame ionization detector and micro flame spectrometer

In this paper we present a miniaturized flame ionization detector and flame spectrometer fabricated using conventional micromachining technologies. The main component of both devices is a micro burner unit, which uses minimal oxyhydrogen to produce a stable miniature flame. The oxyhydrogen is generated at low energy consumption by a miniaturized electrolysis cell, which can be operated by battery. Because of the low oxyhydrogen consumption and the minute scale of the burner unit and electrolyzer the oxyhydrogen is generated as-required, rather than stored as in conventional systems. Thus, there is no explosion hazard and the devices are not only made easily portable, but also safe. Furthermore, these systems possess sensitivity and selectivity that is comparable to conventional systems. Concentrations down to 1 ppm have been demonstrated with the micro flame ionization detector and a detection limit in the ppb range appears within reach. The micro flame spectrometer is undergoing initial development, but measurements based on atomic emission spectrometry demonstrate already a detection limit only 100-fold above levels observed in conventional systems. (C) 2000 Elsevier Science S.A. All rights reserved.