Diffusive Monitoring – A Cost-Effective and Quantitative Approach to Environmental Monitoring

Thermal desorption sorbent sampling tubes for air sampling. Backed up by fast and friendly service, Markes’ tubes provide optimum sampling and analytical performance. Our range includes everything from cost-effective packages of industry-standard tubes to the last word in sorbent tube innovation. Features: Our industry-standard (3½-inch (89 mm) long x ¼-inch (6.4 mm) o.d.) sorbent tubes are available in stainless steel, inert-coated stainless steel and glass. Compatible with thermal desorption instruments manufactured by Markes International, PerkinElmer and Shimadzu. All tubes are permanently labelled with a unique serial number, barcode and sampling flow arrow, so that they are easy to use and track. Further labelling options for tube tracking – includes laser-etching, banding and RFID-tagging (TubeTAG™). Diffusion-locking SafeLok™ options for additional peace of mind. Stringent quality control – our tubes are packed to a tolerance of ±2.5% or better. Application-specific sorbent tubes – optimally packed for applications ranging from air toxics to material emssions testing. Our sorbent tubes can also be ordered conditioned and capped, so that they’re ready for use on arrival. All our sorbent tubes can be supplied: empty for you to pack yourself (or for direct desorption); pre-packed with one sorbent bed for diffusive (passive) monitoring applications; or pre-packed with up to three sorbent beds for pumped (active) monitoring applications. We also supply 4½-inch DAAMS tubes (regular and high-flow, in any of the above materials) – contact us for details.

Robust and easy-to-use soil gas sampler. The VOC-Mole is a stainless steel assembly that is inserted into the ground, allowing soil gas to be sampled onto a sorbent tube, for analysis by thermal desorption (TD)–GC–MS.The VOC-Mole is simple to use and easy to transport, and perfect for any analyst wishing to monitor levels of volatile organic compounds in soil.Features: Organic pollutants pass through holes in the hollow tube and are collected on a sorbent tube. Probe can be left in ground for long periods. Compatible with diffusive and pumped sampling. Use of multiple VOC-Moles in a grid arrangement allows the creation of VOC maps. Special cap prevents ingress of water, wildlife and soil debris. Various pack sizes and probe lengths available. Applications: Surveys of industrial, waste and brownfield sites. Screening of organic pollutants over large areas. Pinpointing of leaks from pipelines and industrial facilities.