Mercaptans, or thiols, are a unique group of organic sulphur compounds. Apart from their very low odour threshold value, they are also very reactive. An adapted sampling technique as well as an optimized analytical method, allows OLFASCAN to quantitatively measure mercaptans. Tertiair butyl mercaptan is added to raw gas so humans can detect the gas by smelling the odour of the added mercaptan.
Mercaptans are sampled using special coated canisters. These are extremely suited for storing these very reactive compounds prior to analysis. A part of the gas is taken out of the canister at the lab and transferred onto a suited sorbent. Both analytical method and analystical measuring device are configured in order to detect mercaptans qualitatively and quantitatively. A very low limit of detection (0.5 - 5 µg/m³) can be obtained for the following 8 mercaptans: