16 Advanced Solutions for Comprehensive Ambient Air Monitoring

Abstract

Abstract Growing concerns over harmful exposure to low levels of hazardous air pollutants has led to increasingly demanding volatile organic compound (VOC) monitoring programs. Regulations are evolving to increase monitoring frequency, expand the list of target compounds and set lower detection limits in ambient air. Alongside this ambient and indoor air research continues to identify new, challenging compounds. There have long been specific standard methods and regulations for subsets of compounds, each using different instrumentation. For example method TO-15 for air toxics requires TD-GC-MS, ozone precursors monitoring uses TD-GC-FID and aldehydes are sampled with DNPH cartridges, analyzed by HPLC. Each compound set has its own challenges. Even so there is a drive to combine all three analyses into a single analytical run with the possibility of monitoring in online and offline. Additional considerations are high levels of humidity and large sample volumes, required to meet lower reporting limits. These require sophisticated trapping and water management techniques. As such removal of water from canister and on-line samples without loss of polar species is paramount for successful analysis of the Ozone Precursors, Air Toxics and oxygenated VOCs. This presentation will address the challenges associated with this complex compound list and show how confident identification and quantitation, with maximum sensitivity, can be achieved using state of the art pre-concentration technology. The cryogen-free methodology allows remote, on-line analysis or off-line canister sampling, all with a sample-to-sample cycle time of <60 minutes, significantly reducing equipment overhead and analysis times whilst enhancing insight into air quality.