We Are Knox...
Clara A. Abbott Distinguished Professor of Chemistry
At Knox: Since 1988
Knox College chemistry professor Larry Welch is interested in the most
basic question: "What is that stuff?" He and his students and collaborators
are working to improve our methods of chemical analysis -- used in
everything from basic lab science to applications in medical research and criminal investigations.
"Initially, my research centered in electrochemistry, which uses electricity to separate components, and in chromatography, which uses a filtering material to do the separation," Welch says. "Now, we're also focusing on spectroscopy -- it's a method that is more widely used, and we received some significant grants for research equipment that have enabled us to broaden the kinds of chemistry research projects that students can undertake."
Welch's work in spectroscopy is based in the luminescence of the lanthanide metals -- the elements between 57 and 71 on the periodic table -- which glow when subjected to radiation. "In particular, we use circularly polarized luminescence to probe terbium complexes," Welch says. Bombarded with radiation, terbium glows brightly -- it's used in fluorescent light bulbs -- which also makes it a good marker, or "probe," because it's easy to measure when attached to the components that make up biochemical compounds.
Welch teaches general chemistry, forensic science, analytical chemistry, and environmental chemistry. He won the Philip Green Wright-Lombard College Prize, the highest award given by Knox College for distinguished teaching and was named to an endowed faculty position, the Clara A. Abbott Distinguished Chair in Chemistry at Knox.
His research has produced papers in electrochemistry, chromatography, and spectroscopy, including the detection of penicillin derivatives, separation and quantitation of pharmaceutical compounds, and the determination of equilibrium constants for terbium.