1. Department of Chemistry, Colorado State University at Pueblo, 2200 Bonforte Blvd, Pueblo, Colorado 81001, National Water Quality Laboratory, U.S. Geological Survey, P.O. Box 25046, Denver Federal Center, Denver, Colorado 80225-0046, U.S Geological Survey, 400 S. Clinton St. Suite 269, Iowa City, Iowa 52240-4105, Department of Chemistry and Biochemistry, Eastern Washington University, Cheney, Washington 99004, and U.S. Geological Survey, 2045 Route 112, Building 4, Coram, New York 11727