1. Restek Corporation, Bellefonte, Pennsylvania 16823, and Chemistry Department, Juniata College, Huntingdon, Pennsylvania 16652
2. Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana 70803
3. Sandia National Laboratories, Albuquerque, New Mexico 87185
4. Restek Corporation, Bellefonte, Pennsylvania 16823
5. Department of Chemistry, University of Texas, El Paso, El Paso, Texas 19968