Greetings! I would like to determine the natural abundance of 15N of ammonium in interstitial water and overlying water in brackish lake. I would greatly appreciate any information i.e. literatures, name of the expert person, or key words to search papers. Searching with key words of "ammonium" and "stable isotope" gave me too much papers of no relations. Sincerely, Masumi ------------------------------------------------------------------- Masumi YAMAMURO (D Sc) Institute of Geology and Geoinformation Geological Survey of Japan AIST Tsukuba Central 7 Tsukuba Ibaraki 305-8567 Japan Tel & Fax 81-298-61-3766 E-mail [log in to unmask] http://staff.aist.go.jp/m-yamamuro/en_Folder/top_english.html +++++ Updated on 25 November 2005 +++++ -------------------------------------------------------------------