(NIST: Gaithersburg, MD) -- A chemist at the National Institute of Standards and Technology (NIST) has demonstrated a relatively simple, inexpensive method for detecting and measuring elusive hazards such as concealed explosives and toxins, invisible spoilage in food, or pesticides distributed in soil by wind and rain.

The prototype method is more sensitive than conventional techniques for detecting traces of these materials, which are polar—like water molecules, having distinct electrically positive and negative ends—and don't readily evaporate.

As described in a new paper by NIST researcher, Tom Bruno, published in the August 2009 issue of Journal of Chromatographic Science titled “Simple, Quantitative Headspace Analysis by Cryoadsorption on a Short Alumina PLOT Column,” Bruno enhanced a technique called “headspace analysis,” which is the detection and analysis of trace levels of chemical compounds from a solid or liquid that are released into the surrounding atmosphere.

Bruno’s enhancements greatly improve the efficiency of sample collection, for the first time making the technique suitable for detecting low concentrations of polar, low-volatility, compounds such as explosives. Preliminary results indicate the method is sensitive enough to measure amounts of target materials that constitute as little as 0.0000002 percent of a sample.

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