Storage of Nitrous Oxide on Molecular Sieves

Abstract

A procedure was developed for storing the N2O in 50‐mL air samples on activated molecular‐sieve type 5A in 60‐mL serum bottles. The procedure was equally effective for N2O concentrations of 1 and 10 µL · L−1 and storage times up to 6 weeks. Blank values for sieves stored 3 to 5 months after activation ranged from about 0.04 ± 0.002 to 0.05 ± 0.005 µL · L−1. Allowing freshly activated sieves to cool in air before capping the bottles increased blank values and variability to unacceptable levels. Nitrous oxide fluxes from soil > 10 g N · ha−1 · d−1 could be reliably determined when the storage procedure was used in conjunction with a chamber method for N2O flux measurement.

Improving process-based estimates of N2O emissions from soil using temporally extensive chamber techniques and stable isotopes

“…Our STGTS concept uses zeolite molecular sieve 5A to quantitatively trap N 2 O and CO 2 , similar to past trace gas trapping approaches (Ryden et al 1978(Ryden et al , 1979Duxbury and Voghel 1982;Egginton and Smith 1986;Godbout et al 2006a, b;Kumagai and Koda 1999;Pérez et al 2000;Skiba et al 1992;Yoshida and Matsuo 1983); however, continuous sampling for extended time periods using such approaches would result in trap saturation. Further, as water interferes with the retention of trace gases on molecular sieve, large quantities of water vapor would need to be removed.…”