1. Department of Chemistry, University of Arizona, Tucson, Arizona 85721 (M.J.P., M.B.D.); Thermo Jarrell Ash Corporation, 8E Forge Parkway, P.O. Box 9101, Franklin, Massachusetts 02038-9101 (R.G.S., P.M.M.); and Creative Solutions, Box 368, Sandown, New Hampshire 03873 (S.B.S.)