ACS Award in Chromatography

Sponsored by Supelco

It's a lucky thing for chemistry that John G. Dorsey never had to resort to his second-choice college major of political science. His decision to study chemistry has led to a long and successful career as an analytical chemist at the forefront of separations research. His experimental and theoretical work has given researchers new tools that expand the ability of chromatography to characterize complex samples.

Dorsey, 54, is the Katherine Blood Hoffman Professor of Chemistry & Biochemistry at Florida State University. His interest in science started in elementary school when he eagerly read books about science. In high school, he was inspired by his physical sciences teacher, who also taught him chemistry, making it "very fun and exciting." Still, Dorsey knew that chemistry would be a challenging major. He followed through with his interest at the very small Transylvania University in Lexington, Ky., which had only two chemistry professors.

After receiving his undergraduate degree, Dorsey wanted to "find out what the real world was about" and worked in chemical analysis in industry. His adventures in industry inspired a desire to learn more about the problem solving behind measurement science. After two years as a bachelor's-level chemist, Dorsey began his graduate studies at the University of Cincinnati in the research group of T. W. Gilbert, a separations scientist who proposed studying a new detector for liquid chromatography. Dorsey received his Ph.D. in analytical chemistry in 1979.

The demand for research and instruction in separations science enabled Dorsey to take a position as an assistant professor at the University of Florida shortly after he received his doctorate. An early research paper published in Analytical Chemistry with Joe P. Foley, a professor of analytical chemistry at Drexel University in Philadelphia, introduced the "Foley-Dorsey equation," now the recognized standard for calculating the resolving power of a separation step. Prior to this 1983 paper, the number of theoretical plates (a performance indicator for separations) had been based on an incorrect assumption of the peak shape, causing calculated values to be skewed.

Luis A. ColÓn, a chemistry professor at the State University of New York, Buffalo, points out that in his research Dorsey "addresses important problems and shows useful solutions to those problems." The development of aqueous micellar mobile phases for reversed-phase liquid chromatography (RPLC) was greatly enhanced by Dorsey's solution to the problem of preserving peak sharpness in the new method. Additional research discovered new ways to use the technique. "He was the first to show the applicability of reverse micelles as a mobile phase for normal-phase chromatography," ColÓn says.

Much of Dorsey's research has focused on expanding the understanding and usefulness of RPLC. He argued that retention arises from a partitioning mechanism, not from adsorption, and proved the importance of entropy in the partitioning process. This understanding of retention processes led to the discovery of a new procedure that reduced equilibration times in gradient elution RPLC by up to 75%. For biological applications, he developed new stationary phases that allow a thermodynamically accurate estimate of bioavailability, leading to the use of RPLC to mimic biological partitioning.

In addition to research, Dorsey makes important contributions to the literature as an editor of the Journal of Chromatography A. From 1990 to 1998, he led the preparation of the biennial reviews of high-performance liquid chromatography published by Analytical Chemistry. His favorite way to contribute to the scientific community has been by guiding his graduate students; so far he has graduated 52 Ph.D.s. "I'm very proud of that number. My grad students have been a great source of fun and joy in my life. I'm very proud of them," Dorsey says. His students will have a bright future, he believes. "The world is complex; Mother Nature still has an awful lot of secrets that she's not let us on to. Separation science is very necessary."

The award address will be presented before the Division of Analytical Chemistry.-Melody Voith