Sampling Failure
Saturation of a collection medium during air quality monitoring results in the loss of target analytes through the outlet of the sampling device. Occurrence of sorbent tube breakthrough indicates that the volume of air sampled exceeded the capacity of the adsorbent material. This error leads to an underestimation of the chemical concentration in a factory or lab.
Mechanism Description
Air is drawn through a tube packed with charcoal or polymer beads to trap volatile chemicals. During sorbent tube breakthrough, the chemicals travel through the primary bed and appear in a secondary back-up bed. Finding more than ten percent of the total mass in this second section signifies a failed test.
Prevention Strategy
Proper calibration of the pump flow rate and selection of the correct sorbent mass prevent data loss. Technicians avoid sorbent tube breakthrough by estimating the expected contaminant levels before setting the sample duration. Using two tubes in series provides a safety margin for high-concentration environments.
Impact Analysis
Reliable exposure monitoring for workers in dyeing or finishing plants depends on preventing this condition. Any evidence of sorbent tube breakthrough requires the immediate invalidation of the air quality sample and a repeat of the procedure.
