Benzene is classified as a known carcinogen and one of the USEPA’s 30 urban air toxics that present the greatest threat to public health. Methods for characterisation of benzene in air typically use canister or sorbent sampling followed by laboratory analysis. Continuous measurement of benzene in air is achieved via auto-gas chromatography or open path methods but these have high capital and operating costs preventing widespread community deployment.
In this presentation we will report on the development of a sensor-based benzene instrument capable of continuous measurement of benzene in ambient air at a much lower price point compared with existing technologies making it suitable for higher density community monitoring. The technology is based on a specifically designed temperature programmed desorption bed, PID or MOx sensor and smart deconvolution algorithms to distinguish and quantify benzene among other aromatics and VOCs in ambient air. Power consumption is low enough to make solar power a viable option. Data is reported at 15-minute intervals. Laboratory evaluation against reference standards indicate a 0.2 ppb detection limit and linearity up to 100 ppb.
We will also report the results of field trials of the instrument against field deployed, continuous auto-GC instruments at a variety of locations across the US and Canada. Data quality in terms of accuracy, precision and cross-interferences will be presented and discussed.Keywords: Benzene sensor ambient monitoring
.jpg "Geoff Henshaw, Ph.D (he/him/his) photo")
