Our next webinar is scheduled for Thursday October 5th, 2017 at noon eastern, featuring Dr. Tadeusz Górecki.
SiREM’s webinar series features guest speakers who are subject matter experts to provide the latest information on technology advances in environmental remediation and site characterization. The webinars will combine recent research and development activities for new and emerging contaminants and technologies with real word applications to characterize and remediate contaminated sites.
We hope you will join us for our next webinar:
Recent Advances in Permeation Passive Sampling of VOCs
Dr. Tadeusz Górecki (Professor, University of Waterloo) will discuss passive sampling for assessing contaminant concentrations in indoor air, outdoor air and soil gas. Passive sampling is an attractive alternative to active sampling with Summa canisters or pumped ATD tubes – it is generally simpler and less expensive to deploy passive samplers on a large scale. A permeation passive sampler equipped with a polydimethylsiloxane (PDMS) membrane has been developed at the University of Waterloo and is available commercially from SiREM under the name Waterloo Membrane Sampler (WMS). The suitability of the WMS for compound-specific isotope analysis (CSIA) will also be discussed. A recently developed mathematical model allows prediction of the uptake rate and its changes during sampling based on the properties of the analyte and the sorbent. The model provides a valuable tool to assess changes in the uptake rate during sampling, to assign suitable exposure times at different analyte concentration levels, and to optimize the dimensions of the sampler in a manner that minimizes these changes during the sampling period.
Hester Groenevelt will present case studies where the WMS sampler was used for analysis of indoor and outdoor air and soil gas.
Passive sampling is based on free flow of analyte molecules from the sampled medium to a collecting medium due to a difference in chemical potential of the analyte between the two media. It is generally simpler and less expensive to deploy on a large scale compared to active sampling. Passive samplers can operate in the kinetic region, in which case the amount of analyte collected is proportional to its time-weighted concentration in the sampled medium, or in the equilibrium region, in which the amount collected is proportional to the analyte concentration around the time of sampler retrieval. Kinetic samplers require a well-defined uptake rate-limiting barrier for the results to be quantitative. When the barrier is made of a semi-permeable material (e.g., polydimethylsiloxane