1. a Chemistry Department, Louisiana State University, Baton Rouge, LA 70803 and Occupational Safety and Health Administration, 2156 Wooddale Blvd., Hoover Annex, Suite 200, Baton Rouge, LA 70806
2. b Chemistry Department, Louisiana State University, Baton Rouge, LA 70803 and Reiszner Environmental and Analytical Laboratory, P.O. Box 3341, Baton Rouge, LA 70821
3. c Chemistry Department, Louisiana State University, Baton Rouge, LA 70803 and West-Paine Laboratories, 7979 G.S.R.I. Avenue, Baton Rouge, LA 70808