1. Contribution from the R & D Center, Mitsui Chemicals, Inc., 580-32 Nagaura, Sodegaura, Chiba, 299-0265, Japan; Mitsui Chemical Analysis & Consulting Service, Inc., 580-32 Nagaura, Sodegaura, Chiba 299-0265, Japan; and Mitsui Chemical Analysis & Consulting Service, Inc., 6-1-2 Waki, Waki-Cho, Kuga-Gun, Yamaguchi 740-0061, Japan