US boffins show off real-life tricorder

Star Trek technology comes to earth.

Researchers at Purdue University in the US have invented a prototype 'tricorder' similar to the fictional device featured on Star Trek.

The handheld device is a miniature mass spectrometer combined with a technique called desorption electrospray ionisation, or DESI, that can perform on-the-spot chemical analysis to test foods for dangerous bacterial contaminants.

"Conventional mass spectrometers analyse samples that are specially prepared and placed in a vacuum chamber," said R. Graham Cooks, the Henry Bohn Hass Distinguished Professor of Analytical Chemistry at Purdue's College of Science.

"The key DESI innovation is performing the ionisation step in the air or directly on surfaces outside the mass spectrometer's vacuum chamber.

"We like to compare it to the tricorder because it is truly a handheld instrument that yields information about the precise chemical composition of samples in a matter of minutes without harming the samples."

Unlike conventional mass spectrometers, which can weigh more than 140Kg, the new device weighs less than 9Kg and can be used in the field.

The research team has used it to analyse clothes, foods and tablets, and to identify cocaine on $50 bills in less than one second.

Purdue has set up two spin-off companies to market the invention. Nasa has yet to call, however.