Focus: Separation Science FEATURE

Randall C. Willis

Historica chromatographica

A timeline tracing the classic foundation of modern chemistry

View “Historica Chromatographica” (interactive timeline or PDF)

In many respects, perhaps no one scientific concept has had a more profound impact on the history of the 20th century than chromatography. From Friedrich Goppelsroeder’s first attempts to identify the chemicals that composed dyes, milk, oil, and wine using paper chromatography to Christopher Pohl’s micromembrane ion chromatography suppressors and from R. Gans’s water-softening experiments with zeolites to Dennis Desty’s petroleum analysis by gas chromatography (GC), the achievements of the last century rest on the shoulders of the men and women who dedicated their lives to separating compounds.

Food: Chromatography has been critical to our understanding and development of both agriculture and food. Although it was known that chlorophyll, the chemical engine of plants, was actually a mixture of compounds, it wasn’t until 1903 when Mikhail Tswett used precipitated chalk to separate the mixture into seven distinct species that the compounds could be characterized. Similarly, researchers have recently started using countercurrent chromatography to isolate and characterize the antioxidant catechins from green tea and wine.

Energy: Before scientists could split the atom, they had to split the isotopes, and the early work of T. I. Taylor and H. Urey on the separation of lithium isotopes established the isolation of fissionable uranium (²³⁵U from ²³⁸U) and ushered in the atomic age. Chromatography has also been shown to be critical to petroleum refinement, as sulfur-containing compounds can cause the corrosion of equipment and disrupt the action of catalysts. GC provides a rapid means of determining the precise amount and species of these compounds, even at sub-ppm levels.

Environment: Nature is filled with chemical compounds and ions—both natural and synthetic—that are welcoming or withering, and government agencies have relied on GC or HPLC to measure these nutrients and contaminants. Researchers used GC in the early 1960s to show the presence of DDT in various fish and birds, work that correlated the chemical with declining animal populations and resulted in the insecticide being banned in the 1970s.

Life: In 1956, Elliot Volkin used ion-exchange chromatography to elucidate the key step in the conversion of genetic information to metabolic action. By feeding ³²P to bacteria and infecting them with a virus, he was able to show that the production of viral proteins from DNA moved through an RNA intermediate—the first evidence of messenger RNA. Similarly, early work on the separation of nucleotides and amino acids using liquid chromatography led to medical marvels, like acyclovir.

Of course, these examples only skim the surface, and the following timeline (slide show or pdf) can only give an overview of how, when, and why chromatography came to define the 20th century.

Randall C. Willis is an assistant editor of Today's Chemist at Work. Send your comments or questions regarding this article to tcaw@acs.org or the Editorial Office 1155 16th St., N.W., Washington, DC 20036.

 © 2002 American Chemical Society.