It sounds nice in theory but at such minute levels, you're going to have tons of noise and variation from individual to individual. You'll be able to produce a

It sounds nice in theory but at such minute levels, you're going to have tons of noise and variation from individual to individual. You'll be able to produce a result, but it likely won't have any bearing in reality. In order to offset the noise you'll need to increase your sample size (volume) of air. You can't measure what isn't there, and once you get down to these levels stuff stops becoming distributed uniformly. Have fun becoming friends with the vendors who supply the police their other technology. Must be a great crowd of people! You all can sit around and make jokes about black people and discuss your cut of civil forfeitures.