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 do not readily evaporate.
As described in a new paper,* NIST researcher Tom 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.
The sample collection device consists of several coils of fine tubing just 0.32 millimeters in inner diameter. Bruno modified the inner coating, which efficiently attracts and retains chemicals across its large surface area. The device can be used with a sample-heating oven as part of a laboratory analysis system or taken into the field for sample collection. To extract target molecules from a sample, the coil is placed inside an insulated cylinder and chilled with a cold air stream to minus 40 degrees Celsius. A gas, such as helium, is swept across the sample held in the oven or the coil device, gathering up target molecules along the way, and through the fine tubing. Chilling the coils—part of Bruno’s innovation—makes collection of target molecules more efficient. The tubing is washed with a solvent, or heated, to release the captured molecules for analysis.
Bruno found that the mass of the collected molecules increases with rising oven and sweep gas temperatures, offering a way to detect specific target molecules under particular field conditions. NIST researchers demonstrated the new method using several explosives, including the pure explosive TNT and the plastic explosive mixture C-4. Among other applications, NIST researchers have used the method to improve sampling and analysis of fire retardants in a car interior, a topic of interest because of concerns expressed by some that the “new car smell” may be a health hazard. They also are using the method to detect volatile protein decomposition products in spoiled meats. Environmental applications could include detection of pesticides deposited on soils subject to weathering effects.
The work is supported by the Department of Homeland Security.
* T.J. Bruno. Simple, quantitative headspace analysis by cryoadsorption on a short alumina PLOT column. 2009. Journal of Chromatographic Science, Vol. 47, pp. 569-574, August.
Laura Ost | Newswise Science News
Not of Divided Mind
19.01.2017 | Hertie-Institut für klinische Hirnforschung (HIH)
CRISPR meets single-cell sequencing in new screening method
19.01.2017 | CeMM Forschungszentrum für Molekulare Medizin der Österreichischen Akademie der Wissenschaften
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
19.01.2017 | Earth Sciences
19.01.2017 | Life Sciences
19.01.2017 | Physics and Astronomy