Adsorbent media for worplace nitrous oxide sampling

Nitrous oxide (N2O) is used as an anesthetic agent in medical, dental, and veterinary operatories. Several toxicological studies have shown that occupational exposure to N2O causes adverse effects on health. The actual method developed by INRS is based on the passive sampling of N2O on a thermal desorption tube filled with 750 mg of molecular sieve 5Å. This method has strong limitation due to the relative low affinity between the adsorbent, 5Å, and the adsorbate, N2O molecules, and therefore to the retrodiffusion phenomena as the concentration of N2O decreases during the sampling. Several inorganic media have been tested in order to improve the actual sampling method. The ion-exchanged zeolite BaZSM5 appears as the most suitable zeolite for the sampling of nitrous oxide and its analysis by thermal desorption.