A portable cryogenic collection system has been constructed for the isolation of atmospheric nitrous oxide (N2O) and carbon monoxide (CO). Ambient air enters the system at a rate of 10 L/min, and N2O condenses in a specially designed stainless steel ultrahigh-efficiency collection (UHEC) trap. The CO is next oxidized to CO2 and removed by a second UHEC trap. In conjunction with drying agents, the UHEC traps remove greater than 99.9989% of atmospheric carbon dioxide (CO2) that would otherwise interfere with CO-derived CO2 analysis. The oxygen in the N2O and CO-derived CO2 samples is subsequently separated for high-precision mass spectroscopic analysis. This system is unique in that it provides for in situ collection and permits simultaneous measurement of the 18O/16O and 17O/16O ratios in N2O and CO. Results are presented for a series of trials run to determine the ultimate collection efficiency of the UHEC cryogenic traps.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry