The importance of antioxidant defenses in the maintenance of general well-being and optimal health is becoming recognized among health specialists and the general public. Furthermore, elevated levels of free radical generation and consequent oxidative damage to macromolecules, have been implicated in an increasing number of progressive neurological disorders, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and epilepsy. Antioxidant therapy is being tested experimentally for all the above diseases. Antioxidant utilization has also being proposed as a possible means of reducing the very high incidence of colon cancer in the US. The use of antioxidants may be of special value to certain high risk segments of the population such as smokers. Taken together, these issues suggest that this is an appropriate time to promote the development of a convenient means of quantifying the parameter of total bodily oxidant status. This application plans to develop an inexpensive, portable, compact and easy-to-use chromatographic kit to allow a rapid and accurate quantitative analysis of expired ethane. The measurement of exhaled hydrocarbon gases constitutes a totally non-invasive means of estimating oxidative stress in living organisms. We propose to develop a simple to use, hand-held, robust breath analyzer for home-care diagnostic application. The design and fabrication of this analyzer is based on newly emerging micro-machining technologies