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

Abstract

Accurate and precise monitoring of volatile organic compounds (VOCs) and volatile sulfur compounds (VSCs) is critical to protect individuals against occupational and environmental exposure. Whole-air sampling containers are commonly employed in monitoring, such as fused-silica lined (FSL) canisters, polyvinyl fluoride (PVF) bags, and foil-lined bags. However, these containers have not yet been fully validated, and previous recovery studies are weakened by contradictory findings, short study time, no humidified samples, and unfeasibly high concentrations of VOCs and VSCs. This study evaluated FSL canisters, PVF bags, and foil-lined bags for the recovery of VOCs and VSCs over a period of 20 and 14 days, respectively. This recovery evaluation aimed to quantify the recovery over time 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 500 ppb for VSCs) and “low” concentration (1 ppb for VOCs and 7 ppb for VSCs). Containers were analyzed intermittently throughout the evaluation period, and sample results were modeled using a first-order natural decay model. From the findings, modeling constants were determined by regression, and a majority (70%) of VOC and VSC models were found to be a good fit (R² > 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 longer than previously believed. FSL canisters showed a full recovery (>90%) for all VOCs and VSCs over the entire length of the evaluation (20 days for VOCs, 14 days for VSCs). Foil-lined bags were found to have lower recoveries for all VSCs compared to PVF bags.