Device spots food, air dangers

WEST LAFAYETTE, Ind., Dec. 29 (UPI) -- U.S. researchers said Thursday they have developed a new instrument that can quickly determine if food or air has potential biological dangers.

Using a technique called desorption electrospray ionization, reseachers said thay may be able to create a new class of fast, accurate detectors for applications ranging from food safety to homeland security, said R. Graham Cooks, professor of chemistry at Purdue University.

The new procedure can identify bacteria in minutes without requiring special preparation, as with laboratory mass spectrometers. Cooks will report his findings with the device in the Jan. 7 issue of the journal Chemical Communications.

The procedure involves spraying water in the presence of an electric field, causing water molecules to become positively charged "hydronium ions." Ionized molecules are vacuumed from the surface into the mass spectrometer, where the masses of the ions are measured and the material analyzed.

Such a system could alert employees in the food and healthcare industries to the presence of pathogens, and could provide security personnel with a new tool for screening suspicious suitcases or packages. The device can measure molecules at the nanogram level -- a billionth of a gram.

"We can determine the subspecies of bacteria and glean other information by looking at the pattern of chemicals making up the pathogen, a sort of fingerprint revealed by mass spectrometry," Cooks said. "Conventional wisdom says quick methods such as ours will not be highly chemically or biologically specific, but we have proven that this technique is extremely accurate."

"This method could be applied very soon because the hardware is already available," Cooks said.