Active sampling is key to US EPA Method TO‑17, which involves pumping the sample atmosphere onto the sorbent tubes, which are then capped and transported to the laboratory, for analysis by thermal desorption. It is also the recommended sampling approach in other standard methods, including ISO 16017-1, ASTM 6196, Chinese EPA HJ 644 & HJ 734, EN 14662-1, CEN/TS 13649, NIOSH 2549, UK Environment Agency LFTGN 04, and UK HSL MDHS 72.
Pumps for active sampling include ‘grab-samplers’ and battery-powered pumps. By allowing precise volumes from between 20 mL to several hundred litres to be sampled onto tubes, it ensures compatibility with a wide concentration range (sub-ppt to high ppm). Active sampling is compatible with use of multi-bed sorbent tubes for sampling analytes over a wide volatility range and can be used for collecting VVOCs (e.g. propene and chloromethane) through to SVOCs (e.g. dodecyl phthalate and six-ring PAHs)