Sorbent tubes are the most widely used collection media for sampling hazardous gases and vapors in air, mostly as it relates to industrial hygiene.
They were developed by the US National Institute for Occupational Safety and Health (NIOSH) for air quality testing of workers.
Commonly used sorbents include activated charcoal, silica gel, and organic porous polymers such as Tenax and Amberlite XAD resins.
A pump with a calibrated flow rate in ml/min is normally placed on a worker’s belt and it draws a known volume of air through the sorbent tube.
Occasionally, when desorbing the air sample from the sorbent tube, a large portion of the analyte will fail to go into the solution.