00555naa a2200205 a 450000100080000000500110000800800410001910000130006024501190007326000090019265000120020165000120021365000120022565000160023765000090025365300080026270000170027070000180028777300440030516130511995-06-27       1991    bl ---       0--  u    #d1 aCHEN, D.  aExternal-source contamination during extraction-distillation in isotope-ratio analysis of soil inorganic nitrogen.  c1991  aAmônia  aMétodo  aNitrato  aNitrogênio  aSolo  a15N1 aCHALK, P. M.1 aFRENEY, J. R.  tAnal. Chim. Actagv.245, p.49-55, 1991.