New laser spectrometer provides instant analysis

By Maggie Fox, Health and Science Editor

WASHINGTON (Reuters) - A new detector combines a laser with a mass spectrometer to provide on-the-spot analysis that researchers hope will have applications ranging from evaluating a tumor as it is removed to quickly detecting explosives in luggage.

The laser vaporizes tiny samples that can be instantly sampled and analyzed by the spectrometer, and can be used even on living organisms, the team at George Washington University said on Thursday.

"We are talking about less than a second for an analysis," Akos Vertes, a professor of biochemistry and molecular biology at George Washington University, said in an interview.

Vertes and graduate student Peter Nemes say they have used their system to find a drug sample in urine, to detect the chemical changes that accompany color changes in a living plant leaf and to find explosives residue on a dollar bill.

The university has filed for a patent on the system, which Vertes said is the first to use a laser for such instant analysis of living tissue.

Called laser ablation electrospray ionization or LAESI, the system requires a desk-sized space in a laboratory. But smaller spectrometers and lasers could make it portable, Vertes said.

"It is still not pocket-sized," he said.

The laser burns the living tissue, vaporizing some of it and sending particles up into the air in a puff. In a process called electrospray ionization, a stream of electrically charged droplets is shot at the spot, intercepting the particles and merging with some of them to make charged droplets.