The Analysis of Ozone Precursors by AutoGC: The Role of Calibration and Quality Control Strategies in Data Management for Fully Automated Thermal Desorption-GC- FID Systems

The analysis of ozone precursors has been a feature of the EPA air quality surveillance regulations since 1992 with the establishment of Photochemical Assessment Monitoring Stations (PAMS) as part of State Implementation Plans (SIP) for ozone non-attainment areas classified as serious, severe or extreme. At that time, guidance documentation allowed for the measurements of VOC precursors either by canister sampling or by continuous measurement using a GC/FID with a thermal desorber collecting hourly samples. Only a few agencies chose to do continuous sampling and since that time a lot has been learned about the issues associated with the continuous field measurement of VOCs.