Evaluation of an Automated Air Sampling System: LESS™

摘要

Airborne organic compounds may represent various compound classes, may be present in any given atmosphere, and can range in concentration from low percent levels to low part per trillion. The toxicity of organic compounds vary over six orders of magnitude making it a challenge to measure the concentration of potentially hundreds of individual compounds to obtain sufficient information necessary to assess potential health risks associated with a given atmospheric condition. Due to the complexity and variability of organic compounds in air, active sorbent tube sampling provides one of the more versatile options for collection and recovery of an extensive range of chemicals of concern. Currently, most active sorbent tube sampling is a manual process using a single air sampling pump and tubing to collect one sample and, in some cases, one duplicate or distributive pair sample (parallel samples with differing volumes - i.e. 1 and 4L). This type of manual sampling is limited, labor-intensive and may not provide the high-spatial or temporal dense data required to estimate risk levels or determine the source for the chemical(s) of interest. Additionally, manual sampling does not allow the ability to record flow rates and sample duration real-time which can lead to inaccuracies or invalid samples. To address these limitations, Signature Science LLC developed and is manufacturing a new active air collection device: the Logistically Enabled Sampling System™ (LESS™). This paper illustrates the uniqueness and utility of the LESS™ concept, presents comparison test data to a manual air sampling pump, and data from a Spring 2012 vapor intrusion (VI) study.