It’s hard to imagine an analytical chemistry lab today without gas chromatography/mass spectrometry (GC/MS), the powerful and ubiquitous tool widely used by chemists to identify individual substances in a mixture.
But before the mid-1950s, the combination of gas chromatography and mass spectrometry was not yet available. The invention of GC/MS by scientists at Dow Chemical in 1955 changed the course of history and was honored with a National Historic Chemical Landmark by the American Chemical Society during an event on June 8 in Midland, Michigan, the city in which Dow was founded and the birthplace of GC/MS.
To recognize the significant contribution of this invention in the history of chemistry, ACS president Bonnie Charpentier presented a commemorative plaque to representatives from Dow. The event, held in conjunction with the 50th Central Regional Meeting of ACS, also in Midland, was hosted by the ACS Midland Section, which is celebrating its 100th anniversary this year.
“Through this designation, we pay tribute to the vision and ingenuity of the Dow scientists, Fred McLafferty and Roland Gohlke, who first combined gas chromatography and mass spectrometry more than 60 years ago,” Charpentier says. “In doing so, they created some of the most ubiquitous, powerful tools in the analytical toolbox.”
Modern-day applications of GC/MS include analyzing the purity of new pharmaceuticals, detecting chemical warfare agents and explosives, screening athletes’ urine for banned performance-enhancing substances, and analyzing soil samples from Mars.
To couple gas chromatography with mass spectrometry, McLafferty and Gohlke had to first devise an apparatus that could sample just a small amount of material coming from the gas chromatograph. They then collaborated with Bendix Aviation’s William Wiley and Daniel Harrington, who had developed a very fast mass spectrometer, to couple their gas chromatograph with the Bendix mass spectrometer. McLafferty and Gohlke successfully demonstrated the utility of their rudimentary instrument by analyzing a mixture of acetone, benzene, carbon tetrachloride, and toluene, producing characteristic spectra for each individual compound.
After convincing Dow to purchase a Bendix mass spectrometer, and after additional experimentation, Gohlke and McLafferty presented the researchers’ findings at an ACS national meeting in 1956. Gohlke published a paper about the work in Analytical Chemistry in 1959.
The first commercially successful GC/MS device debuted in 1965 by LKB Instruments. Other companies followed, including PerkinElmer, Hewlett-Packard, and Agilent Technologies. Over the years, the instrument became smaller and less expensive. Technological developments made possible the creation of libraries of mass spectra, with computers being used to identify the chromatographic peaks.
“It isn’t widely known that GC/MS was invented here in Midland,” says Wayde Konze, senior R&D director for analytical sciences at Dow. “That will change with the recognition of the National Historic Chemical Landmark. Dow has a strong tradition of innovations in analytical chemistry and across the entire field of chemistry. That tradition is alive and well today as inventive scientists continue to solve hard problems and push the boundaries of what is possible.”
ACS established the landmark program in 1992 to recognize seminal events in the history of chemistry and to increase awareness of the contributions of chemistry to society. Past landmarks include the discovery and production of penicillin, the invention of synthetic plastics, and the works of such notable scientific figures as educator George Washington Carver and environmental activist Rachel Carson. For more information about the National Historic Chemical Landmarks program, visit www.acs.org/landmarks.