Purdue News

March 9, 2006

New handheld instruments to transform explosives detection, environmental monitoring

WEST LAFAYETTE, Ind. — Researchers from Purdue University who have developed battery-powered, miniature instruments that could one day be deployed in wireless sensor networks in airports, subway systems and office buildings will showcase the technology during a weeklong conference beginning March 12.

Christopher Mulligan uses Purdue's Mini 10 portable spectrometer
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Analytical chemists recently have used prototypes of the handheld mass spectrometers to detect minute traces of triacetone triperoxide, or TATP, which was used by terrorists in last year's London subway bombings and is a common explosive found in improvised explosive devices.

"It's one thing to detect a substance, but it's another thing to be absolutely certain of its composition, which is what you get with mass spectrometry," said R. Graham Cooks, the Henry Bohn Hass Distinguished Professor of Analytical Chemistry in Purdue's College of Science.

Members of the Purdue team will run a live demonstration of the miniature mass spectrometers at an evening poster session on Sunday (March 12) during the 57th Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy, which will take place in Orlando, Fla., on March 12-17. Zheng Ouyang, an associate research scientist in the Cooks group, will present a lecture describing details of the portable instrument on Thursday (March 16), and the group also will describe other aspects of their miniaturization work during a poster presentation on the final day of the conference. The most updated prototype instrument will be on display throughout the entire week at a booth sponsored by the Purdue Department of Chemistry.

Mini 10 portable mass spectrometer
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Mass spectrometry works by first turning molecules into ions, or electrically charged versions of themselves, which can be more easily manipulated, detected and analyzed based on their mass. Scientists in Cooks' lab have developed technology making it possible to speed up and simplify the use of a mass spectrometer, an analytical device that in its conventional form has been long established in modern laboratories. The Purdue research team has constructed miniature versions of the normally large and delicate laboratory equipment, creating instruments that are lightweight, yield results in a matter of seconds and are accurate enough to be used for airport security and other homeland security applications. Cooks' research group has designed and built a portable instrument, named the Mini 10, that is roughly the size of a shoebox and weighs about 10 kilograms (22 pounds), compared to about 30 times that weight for a conventional mass spectrometer.

Researchers also envision future wireless networks linking many of the devices together to constantly sniff the air for chemical or biological warfare agents in buildings and critical locations such as subway stations and airports, Cooks said.

Conventional air monitoring methods involve collecting samples and then testing them in a laboratory.

"What we are talking about is something that monitors the environment in real time," Cooks said. "This technology is practical because it is portable, rugged and accurate."

Cooks also has developed a wandlike probe that can be passed over objects to quickly analyze surfaces.

Researchers using the Mini 10 have detected one nanogram, or a billionth of a gram, of TATP, which is about one-millionth the mass of a grain of sand. Such a system could alert security personnel to suspicious suitcases or packages because bomb makers handling explosives are likely to transfer minute chemical traces to the outsides of containers.

"TATP is difficult to detect with most other technologies," Cooks said.

Materials are readily available to produce TATP, which has been used by insurgents in Iraq to make improvised explosive devices. The federal government has recently set aside tens of millions of dollars for research aimed at detecting TATP, Cooks said.

The portable system also has been used to detect other explosives, including TNT and plastic explosives.

"We really don't know of any explosives that we can't detect," said doctoral student Justin Wiseman. "We started with TNT, went on to plastic explosives, then eventually to TATP."

In addition to the Mini 10, the Purdue Department of Chemistry booth also will feature the department's research in alternative energy, drug design and delivery, and advanced materials.

Cooks' team is associated with several research centers at, or affiliated with, Purdue, including the Bindley Bioscience Center, the Indiana Instrumentation Institute, Inproteo (formerly the Indiana Proteomics Consortium), and the Center for Sensing Science and Technology. Griffin Analytical Systems, located at the Purdue Research Park, has the rights to commercialize miniature mass spectrometers and also will have a display in the conference exhibition.

Funding for Cooks' research was provided by the National Science Foundation, Office of Naval Research and Prosolia Inc., through the Indiana 21st Century Research and Technology Fund.

Writer: Emil Venere, (765( 494-4709, venere@purdue.edu

Source: R. Graham Cooks, (765) 494-5263, cooks@purdue.edu

Purdue News Service: (765) 494-2096; purduenews@purdue.edu

 

Note to Journalists: The talk on Thursday (March 16) by Zheng Ouyang will be at 4:05 p.m. in the Orange County Convention Center, Room 203A. The poster presentation, which will include a live demonstration of the Mini 10 mass spectrometer, will be on Sunday (March 12) during the “New Developments in Analytical Instrumentation and Software” session from 2-7:30 p.m. in the Valencia Ballroom. The second poster presentation, on Thursday, will be during the Homeland Security and Forensics session, 9:30 a.m. to 2 p.m. in Hall A1 of the exposition floor. The Mini 10 mass spectrometer also will be on display in a booth sponsored by the Purdue Department of Chemistry during the conference on the exposition floor. Also, video of researchers working with the Mini 10 in Cooks' lab is available by contacting Emil Venere, (765) 494-4709, venere@purdue.edu.

 

PHOTO CAPTION:
Doctoral student Christopher Mulligan uses Purdue's Mini 10 portable spectrometer to scan the outside of a backpack worn by Adam Keil, a postdoctoral research associate. The shoebox-size instrument is about 30 times lighter than conventional mass spectrometers and can be battery powered. (Purdue News Service photo/David Umberger)

A publication-quality photo is available at http://news.uns.purdue.edu/images/+2006/cooks-portable-spectrometer.jpg

PHOTO CAPTION:
Researchers at Purdue have created a miniature mass spectrometer that promises to have applications in everything from airport security to medical diagnostics. Pictured here is the latest prototype, the Mini 10 portable mass spectrometer, which is roughly the size of a shoebox and can easily be carried with one hand. The instrument is 13.5 inches long by 8.5 inches wide by 7.5 inches tall and weighs 10 kilograms (22 pounds), compared to about 30 times that weight for a conventional mass spectrometer. It also can run on battery power. (Purdue News Service photo/David Umberger)

A publication-quality photo is available at http://news.uns.purdue.edu/images/+2006/cooks-portable-spectrometer2.jpg

 


ABSTRACT

Handheld Rectilinear Ion Trap Mass Spectrometer

Ouyang Zheng, Graham R. Cooks, Liang Gao,
Sameer Kothari, and Song Qingyu

The high sensitivity, high selectivity and wide applicability of mass spectrometry make it an extremely valuable method of chemical analysis methods. However, a limitation to in-field applications of mass spectrometry, including the detection of the terrorist chemical weapons and general environmental monitoring, is the size of the instrument. A handheld tandem mass spectrometer, Mini 10 networking mass spectrometer, has been recently developed to provide a solution to this problem. This miniature mass spectrometer is the size of a shoebox, 13.5" L x 8.5" W x 7.5" H, weighs 10 kg and power consumption is less than 75 W. A rectilinear ion trap with high trapping capacity is used as the mass analyzer and the compact vacuum pumping system consists of a KnF UN84.3 two stage diaphragm pump and a Pfeiffer TPD 011 turbo molecular drag pump. A handheld computer with a touch screen is attached to the instrument to run the user interface through which commands are sent to a process board. A high voltage board is used to provide the lens voltages and a compact RF circuit provides the RF signal to drive the ion trap. Internal EI is used for ionization and the mass-analyzed ions are detected by an electron multiplier. The Mini 10 has wired and wireless communication capability and can be controlled remotely. A network sensor system has been designed based on the Mini 10 and programs have been developed to monitor multiple sensors and to generate alarms based on the analysis of the data.


 

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