Encouraging young engineers in a CSI world

Hey, kids, here are five reasons why you should consider an engineering career:

  • Buried corpses
  • Rotting chickens
  • C4 explosives
  • Drs. Tom Bruno and Tara Lovestead.

The last two are entwined with the first three.Bruno and Lovestead are research chemists at the National institute of Science and Technology (NIST) who have reported a novel approach to finding where hidden bodies are buried. Their work–and how it's being publicized–are important signs that societal attitudes toward engineers are moving in a positive direction.

Their method was touted in a recent NIST announcement that played up the CSI angle: How do you find buried corpses that killers don't want found?Hollywood has made finding corpses sexy, but the bigger applications for the detection method are homeland security (explosives) and food safety (poultry spoilage).

Here's the technology : Lovestead and Bruno, writing in Analytical Chemistry as well as Forsensic Science International , describe a high sensitivity, dynamic headspace analysis technology that uses cryoadsorption on short-alumina-coated PLOT (porous layer open tubular) columns. (See graphics below ).

How it works: The PLOT column, using a motorized pipette, sucks in air samples at ambient temperatures. This is done just above the surface of the soil (or even cement, in the case of mob hits) or is inserted in the soil or a drilled hole in the cement. The device detects trace amounts of ninhydrin-reactive nitrogen (NRN) that collects in air pockets above and close to gravesoil.

“You're looking for nitrogen compounds that fix onto ninhydrin, a chemical used to bring out latent fingerprints,” Bruno said in an interview. “Investigators always carry a can of this with them.”

This trapped decomposing protein is put into a solution of ninhydrin (2,2-Dihydroxyindane-1,3-dione, for those taking notes) and, when combined, it fluoresces–what's known in the business as Ruhemann's purple.

The NIST team used alumina as the adsorbent but believes that silica, porous polymers, clays, organo-clays, and porous graphite works as well.

Why is this cool?
Because headspace analysisis tricky when you're dealing with low volatility compounds (i.e.proteins) and compounds in trace amounts. It requires long collectionperiods, and existing trap instruments just aren't sensitive enough.

NIST is working with a well-known systems company to commercialize the technology. Something could come to market within a year . (Bruno wouldn't tell me which company, and I suspect if he had, I'd end up in a future grave-detecting experiment).

Beyond corpse detection
This application is really more important in explosives detection and food safety (and represents, arguably a bigger and more profitable market than forensics).

In the paper for Analytical Chemistry, the authors point out the importance:

High explosives have extremely low vapor pressures, making detection of the explosive difficult. And some components that vaporize easily in plastic bonded explosives (C4 or Semtex, for example) have legitimate uses.


Bruno uses an example of a shipping container aboard a freighter. How can you efficiently and cost-effectively run security checks on the contents?

“What makes this approach unique is that the trap is a capillary. It's really tiny. At low temperatures, it's very efficient. We can trap, no p roblem, 1 part per billion and do analysis of it,” he said.

Lovestead and Bruno also have applied their headspace-analysis technique to measuring when chicken has spoiled. Preventing salmonella outbreaks would be a huge benefit.

Why should we care about this? Slowly, Hollywood is changing its tune about science, shifting away from the portrayals of scientists and engineers as pocket protector-wearing social goobers to highlighting heroic characters in shows like CSI and Numbers . NIST's communications team has picked up on the vibe.

Demonstrating the ap plication of abstract technologies is the key to building interest among kids. Thousands of teenagers are now streaming into swelling forensic-science degree programs across the country. Those departments are just a stone's throw from the engineering school.



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