The Recovery of Volatile Organic Compounds and Volatile Sulfur Compounds in Fused-Silica Lined Canisters, Polyvinyl Fluoride/Tedlar Bags, and Foil-Lined Bags

摘要

Accurate and precise monitoring of volatile organic compounds (VOCs) andvolatile sulfur compounds (VSCs) is critical to protect individuals against occupational andenvironmental exposure. Whole-air sampling containers are commonly employed inmonitoring, such as fused-silica lined (FSL) canisters, polyvinyl fluoride (PVF) bags, andfoil-lined bags. However, these containers have not yet been fully validated, and previousrecovery studies are weakened by contradictory findings, short study time, no humidifiedsamples, and unfeasibly high concentrations of VOCs and VSCs. This study evaluated FSLcanisters, PVF bags, and foil-lined bags for the recovery of VOCs and VSCs over a period of20 and 14 days, respectively. This recovery evaluation aimed to quantify the recovery overtime of 64 VOCs and 14 VSCs at practical concentrations in the previously specified containers. To better represent field samples,sample containers were prepared at a relative humidity (RH) of 40%, with each set prepared at a “high” (20 ppb for VOCs and 500ppb for VSCs) and “low” concentration (1 ppb for VOCs and 7 ppb for VSCs). Containers were analyzed intermittently throughoutthe evaluation period, and sample results were modeled using a first-order natural decay model. From the findings, modelingconstants were determined by regression, and a majority (70%) of VOC and VSC models were found to be a good fit (R~2 > 0.8).PVF bags were found to have higher recoveries for many VSCs than foil-lined bags, and were stable for periods similar to or longerthan previously believed. FSL canisters showed a full recovery (>90%) for all VOCs and VSCs over the entire length of theevaluation (20 days for VOCs, 14 days for VSCs). Foil-lined bags were found to have lower recoveries for all VSCs compared to PVFbags.