1. Analysis Research Department, Advanced Technology Research Center, NKK (Nippon Kokan), 1-1, Minami Watarida-cho, Kawasaki-ku, Kawasaki, 210, Japan (M.K., H.M., H.I.); and Department of Industrial Chemistry, Faculty of Engineering, University of Tokyo, 7-3-1, Hongo,Bunkyo-ku, Tokyo, 113 Japan (Y.G.)