Nitrogen in lunar samples

These observations generally have been interpreted to indicate a secular increase in the N/ N ratio in the solar wind from about 2.9 x 10 several Ga ago to perhaps up to 

Marti 2001), also make the analyses prone to atmospheric contamination. Nevertheless, the indigenous component can be separated by a stepwise gas extraction protocol in suitable samples, and three studies all find the isotopic composition of indigenous lunar nitrogen to be enriched in the heavy isotope by 13-17%o relative to the composition of the terrestrial atmosphere (Kerridge et al. 1991a Murty and Goswami 1992 Mathew and Marti 2001). Mathew and Marti (2001) note the approximate consistency of this composition with values reported for the terrestrial mantle but caution that fractionation effects during the formation of the moon are difficult to assess. 

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