About the authors BASIL H. VASSOS is Professor of Chemistry at the University of Puerto Rico in San Juan. He is the coauthor, with Galen Ewing, of the previous three editions of this book and of Electroanalytical Chemistry. He received his PhD in analytical chemistry from the University of Michigan. GALEN W. EWING is Professor Emeritus of Analytical Chemistry at Seton Hall University. He is the author of Instrumental Methods of Chemical Analysis, now in its fifth edition. Dr. Ewing is a Fellow of the American Association for the Advancement of Science, a member of the Society for Applied Spectroscopy, and a divisional counselor of the American Chemical Society. He received his PhD in physical chemistry from the University of Chicago.