What makes the ThermoSorb-N different from other sampling methods?

Most solid sorbents used for airborne nitrosamine sampling produce measurable artifact. When nitrogen oxides in the air react with amines on the sorbent surface, nitrosamines form inside the sampler itself. The result looks like a genuine reading but includes compounds that were never in the air.

In comparative testing, Ellutia passed 100 litres of air containing 1 ppm NO and 1 ppm NO₂ through six common sorbents, each pre-loaded with 50 µg of five amine standards. Every sorbent showed detectable nitrosamine formation:

Activated charcoal produced NDMA at 5.9 µg, NMOR at 7.9 µg, and measurable levels of NDPA, NPIP, and NPYR. Activated alumina, Florisil, silica gel, and Tenax GC all showed formation across multiple compounds. Tenax GC produced 15.5 µg of NMOR alone.

The ThermoSorb-N showed no detectable formation for any compound.

Wet traps (1N KOH and pH 4.5 ascorbic acid) also showed no artifact formation, but they have a different problem: nitrosamines desorb over time and degrade with temperature changes. The ThermoSorb-N retained all collected nitrosamines quantitatively across both time and temperature, with recovery values between 89% and 113% for seven common volatile nitrosamines across concentrations from 25 ng to 1000 ng.

The ThermoSorb-N is the only method tested that eliminated both false positives from artifact formation and false negatives from sample loss.

Want to see the full test data? Download the ThermoSorb-N brochure or get in touch with the team.