Last modified: Monday, February 16, 2009
IU Bloomington chemists develop two new devices to aid life sciences research
FOR IMMEDIATE RELEASE
Feb. 16, 2009
BLOOMINGTON, Ind. -- Indiana University scientists have developed a fast, low-cost, high-precision device that can be used to analyze samples in a wide array of settings -- from atop Icelandic glaciers to the benches of operating rooms.
The technology, developed by IU Bloomington analytical chemist Gary Hieftje and graduate student Michael Webb, is called a "solution-electrode discharge" spectrometer. It allows users to determine what chemical elements are in a solution of unknown makeup. Among its many potential uses, the spectrometer could determine the concentration of the element cadmium in a reservoir or, in medical clinics, determine the presence or absence of selenium in blood extracted from a patient. Hieftje and Webb describe the device and report efficacy tests in the Feb. 1 issue of Analytical Chemistry.
Unlike other spectrometers currently on the market, the one developed by Hieftje and Webb requires little power, is portable (12 inches by 6 inches by 6 inches), and is extremely accurate.
"Its detection power is below parts per billion," Hieftje said. "We've tested it extensively, and found it does a great job of determining the atomic composition of nearly any solution."
That is, the spectrometer can tell whether a sample contains a specific metal, but cannot determine how atoms are arranged. The device can tell whether a sample contains carbon, calcium and sodium, and how much of each, but it cannot differentiate between the molecules fructose and glucose, which contain the same number and types of atoms, but are organized slightly differently.
"This is really a technology for researchers who are interested in the presence of specific atoms, not whole molecules," Hieftje explained.
A portable atomic spectrometer could be a boon to many scientific disciplines, however.
Samples collected in the field or medical examination rooms must be brought to a place where the samples can be analyzed. In the case of field work, that trip could take days. And even when the samples arrive, the spectrometers currently used to analyze samples may take hours to return the result. In medicine, a spectrometric result might be more valuable if arriving early rather than late -- for example, a doctor wants to know whether a blood sample contains a poisonous amount of arsenic.
"Once the sample is prepared, our device only needs 10 seconds to analyze it," Hieftje said.
The technology is not yet on the market. But, Hieftje says, "this one is ready for commercial development. We don't know how much it will cost, but it's very likely to be a fraction of the cost of traditional, much larger devices that offer similar accuracy."
Thanks to a new $714,000 National Science Foundation grant, Hieftje is developing a second, separate technology with IU Bloomington chemist Steven Ray and postdoctoral associate Carsten Engelhard that improves "gel electrophoresis," a common technique that allows life sciences researchers to separate proteins and other large molecules for the purpose of identification.
Hieftje, Ray and Engelhard's variation on the tried and true technology is to make it possible for scientists to also determine whether a separating smudge contains an element of interest, particularly metallic elements like iron, copper and calcium.
Traditionally, metal composition is determined in separate, time-consuming steps. The device Hieftje and Ray are developing would remove those steps -- saving as much as a day in bench work.
"Many of the proteins being separated by gel electrophoresis contain metals," Hieftje said. "This technique would allow researchers to know which proteins contain metals, what the metals are, what the ratio of metal to protein is -- even whether someone has a deficiency."
Still in the process of being perfected, Hieftje, Ray and Engelhard's "pulsed radio frequency glow discharge" device superheats the proteins of interest. Superheating obliterates the proteins but excites any metals contained within. The excited metals produce a signature wavelength of light, letting the detector know whether it's molybdenum or cobalt.
The work described in the Analytical Chemistry review was supported by a grant from the U.S. Department of Energy (DE-FG02-98ER 14890). The radio frequency glow discharge device is being developed with support from the National Science Foundation (CHE 0822114) and Indiana University.
To speak with Hieftje, please contact David Bricker, University Communications, at 812-856-9035 or firstname.lastname@example.org.