DETERMINATION OF ¹⁵N-LABELED DINITROGEN AND NITROUS OXIDE WITH TRIPLE-COLLECTOR MASS SPECTROMETERS.

Equations are derived that permit use of a triple-collector mass spectrometer for determination of **1**5N-labeled dinitrogen (N//2) and nitrous oxide (N//2O) by procedures recently developed for double-collector instruments. These equations are based upon the ratios **2**9N//2/**2**8N//2 and **3**0N//2/**2**8N//2. Triple-collector mass spectrometers have become commercially available during the past decade, and several are currently being employed in agronomic research.