AGAT Laboratories in partnership with SiREM, recently announced that the Waterloo Membrane Sampler™ (WMS) is now available for passive soil vapour sampling exclusively at AGAT.
The Waterloo Membrane Sampler™ (WMS) is a cost-effective, simple-to-use passive sampler for soil vapour. The WMS provides quantitative concentration measurements with similar accuracy and precision to conventional active soil vapour samples collected using Summa canisters or TD Tubes.
The WMS is a permeation-type passive sampler. When it is exposed, the VOCs permeate through the membrane covering the top of the sampler vial, driven by a concentration gradient. The sorbent inside the sampler then traps the vapours and then the mass of each compound is determined by GC/MS at AGAT Laboratories.
Frequently Asked Questions
Unlike other media, the WMS has minimal effect from moisture, wind velocity, or barometric pressure. The hydrophobic nature of the membrane excludes water and also prevents turbulent uptake so the sampler can be deployed in high velocity environments such as soil gas extraction systems.
- The WMS-LUTM is a low-uptake WMS used for vapour concentrations in soil gas. The lower uptake rates mitigate the effect of the sampler starvation that may occur when collecting soil gas, and will allow for quantitative soil gas sampling in drier subsurface conditions.
- The WMS-TMTM is designed for VOC vapour concentrations in soil gas with low permeability or very wet soils.
Is the use of the WMS accepted by the Regulator?
It depends on the jurisdiction. In Ontario, Under “Regulation 153 Vapour Intrusion Guidelines,” the WMS is accepted as alternative sampling media for the collection of soil and sub-slab vapour. There is no prescribed sampling method that is recommended or preferred over another. It is the responsibility of the QP to determine what sampling media would be best for their site.