@article{fdi:010092183,
  title = {{N}itrogen in the {O}rgueil meteorite : abundant ammonium among other reservoirs of variable isotopic compositions},
  author = {{L}aize-{G}{\'e}n{\'e}rat, {L}. and {S}oussaintjean, {L}. and {P}och, {O}. and {B}onal, {L}. and {S}avarino, {J}. and {C}aillon, {N}. and {G}inot, {P}atrick and {V}ella, {A}. and {L}amothe, {A}. and {E}lazzouzi, {R}. and {F}landinet, {L}. and {V}acher, {L}. and {G}ounelle, {M}. and {B}izzaro, {M}. and {B}eck, {P}. and {Q}uirico, {E}. and {S}chmitt, {B}.},
  editor = {},
  language = {{ENG}},
  abstract = {{N}itrogen, because of its abundance and variety of carrier phases, is a unique tracer of physico-chemical processes occurring throughout star and planet formations. {T}he refractory organic matter is commonly considered as the main carrier of nitrogen in the most primitive objects of our {S}olar {S}ystem. {H}owever, nitrogen in the form of ammonium ({NH}4+) was observed in the {I}vuna-type carbonaceous ({CI}) chondrites {A}lais in 1834, and {O}rgueil just after its fall in 1864, as well as more recently on {C}eres, comet 67{P}/{C}huryumov-{G}erasimenko, and possibly on some asteroids. {I}n the present study, we have measured the nitrogen content and isotopic composition in various nitrogen-bearing phases of several samples of the {O}rgueil meteorite, with different degrees of terrestrial weathering. {W}ater-soluble {NH}4+ is present in {O}rgueil at a mean concentration of 0.07 +/- 0.01 wt%, with a mean isotopic composition of delta {N}-15 = +72 +/- 9 parts per thousand ({N}-14/{N}-15 = 254 +/- 2), confirming its extra-terrestrial origin. {I}n the most terrestrially altered sample of {O}rgueil that we analysed, the isotopic composition is delta {N}-15 = +50 +/- 12 parts per thousand ({N}-14/{N}-15 = 259 +/- 3). {NH}4+ is in species that are thermally stable up to 383 {K}, possibly ammonium inorganic/organic salts and ammoniated phyllosilicates. {W}e also show that the nitrogen in {O}rgueil is distributed among the insoluble organic matter ({IOM}) (35 +/- 5 %), ammonium (27 +/- 5 %), and other minor water-soluble species (e.g., nitrate, amines etc.: < 6 %). {T}he remaining nitrogen (34 +/- 14 %) is mainly in an unidentified organic matter ({UOM}), which may be {IOM} lost during its extraction and/or acid hydrolysable functional groups bounded to the {IOM} and/or organic nitrogen trapped within minerals. {T}he three main carriers of nitrogen in {O}rgueil have delta {N}-15 (and {N}-14/{N}-15) values of +32 +/- 1 parts per thousand (264 +/- 0.3) for {IOM}, +39 +/- 16 parts per thousand (262 +/- 4) for {UOM}, and +72 +/- 9 parts per thousand (254 +/- 2) for {NH}4+. {A}lthough {IOM} and {NH}4+ have significantly different delta {N}-15, we cannot exclude that these phases could be compositionally related because {IOM} is heterogeneous in {N}-15. {A}mmonium could have been produced via heating and/or aqueous alteration processes of organic matter in the {CI} parent body. {A}lternatively, or additionnally, ammonium could be a tracer of the accretion and/or later deposit of {NH}3 ice, {NH}3 hydrates, and/or {NH}4+ salts on the {CI} parent body. {A}s shown by previous studies, {R}yugu grains sampled by the {H}ayabusa2 mission ({JAXA}) have heterogeneous compositions at the millimeter scale, with nitrogen concentrations and delta {N}-15 similar or lower than {O}rgueil, possibly because of different parent body processing. {T}he present study suggests that the lack or loss of {N}-15-rich {NH}4+ in some {R}yugu grains may explain some of these differences with {O}rgueil.},
  keywords = {{O}rgueil ; {C}arbonaceous chondrites ; {I}sotope ; 15{N}/14{N} ratio ; {N}itrogen},
  booktitle = {},
  journal = {{G}eochimica et {C}osmochimica {A}cta},
  volume = {387},
  numero = {},
  pages = {111--129},
  ISSN = {0016-7037},
  year = {2024},
  DOI = {10.1016/j.gca.2024.10.001},
  URL = {https://www.documentation.ird.fr/hor/fdi:010092183},
}