ARLINGTON - A University of Texas at
Arlington chemistry professor renowned for his innovations in the field of ion
chromatography has been awarded a nearly $1.2 million grant from NASA to
develop technology that could help pave the way for future human missions to Mars
Purnendu “Sandy” Dasgupta will
use the funds to develop “An Ion Chromatograph for Extraterrestrial
Explorations.” The goal is to create a new system for testing the chemical
composition of extraterrestrial soil. Dasgupta’s
project was one of eight nationwide to be funded recently by the Astrobiology
Science and Technology for Instrument Development grant program of the NASA
During past lander missions,
examinations of Martian soil have been limited by technology that used ion
selective electrodes to probe for specific materials, Dasgupta said. An ion
chromatograph, on the other hand, separates and detects ions, which are molecules
bearing an electrical charge. The device can look at a broad suite of ions
sensitively and identify them with some confidence.
“By creating an
easily portable and robustly-designed ion chromatograph, we’re hoping to
rapidly expand scientists’ knowledge of extraterrestrial geology and
geochemistry,” Dasgupta said. Proving organic ions exist in Martian soil could be a first step to
identifying organic compounds, the building blocks of life.
Past Mars missions
have heated soils to look for organic vapors coming from samples. None have been detected. But if the recent finding of large amounts of
perchlorate in Martian soil proves correct, that discovery would explain why
heating soil never shows any organics - the perchlorate would oxidize
“Although we cannot
address the issue of neutral organics”, Dasgupta said, “with this machine, we
should be able to unequivocally answer if organic ions are present”.
Dasgupta plans to use
low-pressure open tubular columns in the design of his chromatograph for NASA,
making it uniquely designed for storage in the subfreezing temperatures
of space when not in use. The columns typically used for ion chromatography are
packed with polymer or silica beads and filled with an aqueous solution. They
cannot withstand such freeze-thaw cycles.
The new device would enable researchers to search for organic
compounds in a way that is compatible with the chemistry of the Martian soil and
would provide answers to questions about organic compounds on Mars,
said Alfonso Davila, principal investigator at the California-based
Carl Sagan Center for the Study of Life in the Universe and a collaborator on the project.
“If that answer was positive, then the possibility of life on Mars
would gain new strength,” Davila said.
An ion chromatograph
could also detect ions such as nitrate and phosphate in extraterrestrial soil.
These are also very important for life and strategically, for human exploration
beyond Earth, Davila said.
particularly interested in learning more about the presence of perchlorate in
Martian soil, an inferential discovery made by the Phoenix lander in 2008. Perchlorate
is a naturally occurring and manmade chemical used in rocket fuel and
explosives. It is also considered a contaminant that is harmful to human health.
Dasgupta also notes
that perchlorate can be both a producer of oxygen and an energy source. So, its
presence on Mars could benefit future human exploration.
Dasgupta is the Jenkins Garrett
Professor of Chemistry at The University of Texas at Arlington and the
recipient of the American Chemical Society’s 2011 Award for Chromatography. He
invented the electrodialytic eluent generator used in modern ion chromatographs
as a way to electrically generate high purity alkali hydroxides, thereby making
results more reliable.
As a first step in
the four-year project, Dasgupta will design and build an open tubular ion
chromatograph system for Earth-based exploration that weighs three kilograms or
less. Researchers from his lab and the labs of his collaborators, including
students, will then test the device in the challenging environment of the
Atacama Desert in Chile. After that, they’ll refine the machine for use on Mars
and other extraterrestrial bodies.
on the project include: W. Andrew Jackson, associate professor of civil and
environmental engineering at Texas Tech University; Samuel Kounaves, a
professor at Tufts University; and Christopher McKay, a research scientist at
NASA’s Ames Research Center in Moffett, Calif.
Dasgupta’s work is an example of
the innovation under way at The University of Texas at Arlington, a
comprehensive research institution of nearly 34,000 students in the heart of
North Texas. Visit www.uta.edu to learn more.