Eugene F. Barry, PHD, is Professor of Chemistry and Head of the Chemistry Department at the University of Massachusetts Lowell and a recipient of the school's Most Outstanding Teacher Award. He is coeditor of Modern Practice of Gas Chromatography, Fourth Edition (Wiley), the standard reference for the industry. Dr. Barry is author or coauthor of over 100 publications and has several patents. The late Robert L. Grob, PHD, was Professor Emeritus of Analytical Chemistry at Villanova University and a consultant in analytical and environmental chemistry. He coauthored Environmental Problem-Solving Using Gas and Liquid Chromatography and authored Chromatographic Analysis of the Environment, now in its third edition. Dr. Grob published over 250 research publications and held one patent. He was the recipient of the Stephen Dal Nogare Award in Chromatography, the EAS Award in Separation Science, and numerous other awards.