Detection of Chemical Warfare Agents on Surfaces Relevant to Homeland Security by Direct Analysis in Real-Time Spectrometry

Authors: J. Michael Nilles, Theresa Connell, H. Dupont Durst, James A. Laramée
American Laboratory 2008, Sep, 01, 40, 16-20

 

Unlike other analytical methods that necessitate that the surface be sprayed with electrically charged solvents, or that require solvent extraction, DART® leaves the sample surface undisturbed.

Analysis of low-volatility, condensed-phase chemicals on surfaces has been an extremely difficult and long-standing objective in environmental monitoring. When target analytes possess picotorr vapor pressures, the problem of monitoring becomes formidable. As such, any noncontact sampling at atmospheric pressure that does not require solvents or wipes would be a technological breakthrough. In addition, the absence of sample preparation would allow extremely rapid analysis in time-critical situations. Today, such a technology is now available. It is known as Direct Analysis in Real Time1 or DART®™ (JEOL USA, Inc., Peabody, MA).

The U.S. Army has been testing and developing DART® since 2002 for the detection of chemical warfare agents on surfaces. Fast, safe, and accurate detection of chemical agents is critical for protection, security, and decision-making. Sample preparation is seldom a requirement with DART®, since the contaminated surface is simply analyzed directly using a plume of gaseous Rydberg atoms. Unlike other analytical methods that necessitate that the surface be sprayed with electrically charged solvents,2 or that require solvent extraction, DART® leaves the sample surface undisturbed. This is a forensically worthy advantage. Recent findings of chemical warfare agent detection on militarily relevant surfaces in Homeland Security is a new approach to Warfighter safety and counter-terrorism.