Chemical Detective Hot on the Vapor Trail

Today in Taking Measure we asked Presidential Early Career Awards for Scientists and Engineers (PECASE) recipient Tara Lovestead a few questions about her life and work. Tara was recognized for her extensive application of new methods to rapidly and inexpensively detect trace levels of chemicals in vapors, enabling advances in homeland security, forensics, and food safety.

What brought you to NIST?

After I finished my bachelor’s in nutrition at Virginia Tech, I attended The University of Colorado (CU) at Boulder for both my master’s and Ph.D. in chemical engineering. My research focused on ultraviolet (UV) light-curable cross-linking polymer kinetics — a fancy way of saying I studied things like how dental fillings harden under UV light.

Upon finishing my Ph.D., I accepted my first postdoctoral position at the University of New South Wales in Sydney, Australia. The experience was wonderful and helped me see that my skills were transferable to new areas like designing polymer materials for lubricating artificial joints.

After my Australian experience, I moved back to Boulder and adopted an adorable puppy named Ernie! One day while Ernie and I were walking, I bumped into a professor from CU that I used to run races with. He told me about a job at NIST that had just been announced. I followed up on his lead and found out that they were looking for research in detecting the chemical signatures of explosive materials — a very challenging area. I accepted a position as a Professional Research Experience Program (PREP) postdoctoral fellow, but quickly transitioned to a National Research Council (NRC) postdoctoral fellowship and then a staff research scientist.

Why is the research you do important?

I feel that my work is improving the world we live in by making fuels more sustainable, our borders safer, and our quality of life better.

One of my areas of expertise is in determining the properties of petroleum distillates, like gasoline, and other fuels. To get gasoline diesel, kerosene, etc., out of crude oil, it has to undergo an extensive chemical distillation process. I work to figure out the properties of various fuel blends because minor differences in their composition (an extra dash of chemical x in proportion to chemical y) can have a profound effect on the fuel’s performance and other characteristics.

For example, a jet fuel used by the U.S. Navy (JP-5) is specifically designed to be not only difficult to ignite to prevent fires on aircraft carriers, but also to combust at lower pressures, such as those encountered while cruising at 40,000 feet. Without the chemical models that my colleagues and I generate, developing new fuels or fuel blends like this would be prohibitively expensive, technologically risky, and even dangerous.

I’ve also worked on detecting explosives for Department of Homeland Security (DHS) anti-terrorism and border control efforts. The methods DHS use now rely on detecting the explosive material by direct sampling. If you ever had a TSA agent at an airport swipe your hands or bags with a cloth and put it into a mysterious-looking machine, you were directly sampled. That machine heats the cloth to release whatever explosive residue might be on it so that it can be picked up by a mass spectrometer.

DHS came to us because they wanted a way to find explosives by detecting the vapors they emit without having to heat them. The problem is that explosive compounds are typically not very volatile, and thus, there aren’t very many molecules of explosive compounds floating around in the air ready to be sampled. I helped DHS by making the first consistent measurements of these vapors to identify both what is in the air above these materials and how much of those vapors a device could realistically detect.

Not only can we characterize the vapor with this method, but it is also really amazing at detecting very small amounts of chemicals in the vapor. Since our work with DHS we have used this methodology to detect food spoilage, hidden grave sites, arson, drugs of abuse, and sniff out the trace chemicals in natural gas.

My most recent work is aimed at providing measurements to help industry and academia develop a cannabis breathalyzer. This work is important because there is increasing decriminalization of cannabis throughout the U.S., but no reliable way to detect recent use and intoxication from cannabis consumption. We hope that our measurements will lead to a better understanding of the chemistry of cannabis intoxication and provide industry with the measurements they need to develop a useful, reliable and accurate breath-sampling device.

What resources does NIST provide to help you in your research?

I have been amazed at the overwhelming support I have received and options that NIST provided me in caring for my children while building my career as a respected scientist. I have had the opportunity to have my infants less than 300 feet away from me while I continue my research, taking breaks throughout the day to visit and feed them. Having on-site quality child care and a flexible work schedule has made all the difference for me and my family.

Unfortunately, they don’t as yet offer on-site dog-sitting—maybe one day!

If you had unlimited funding for research, what would you study/do?

Studies have shown that animals can detect various diseases by smell, but scientists don’t yet know what vapors the animals are actually smelling to detect these diseases. While there are many advantages to using animals to sniff out diseases, there is a lot of time and money that goes into training them, and there is a risk that they might get distracted or tired on the job.

If I had unlimited funding, I would collaborate with other scientists and researchers to discover what the animals, such as cadaver dogs, are detecting. It may not be one chemical, but an entire suite of chemicals. There is also a lot to be learned from an animal’s ability to sniff very trace quantities of vapors. Ultimately, I would work toward developing vapor detection devices to be used in routine check-ups for detecting things like cancer or heart disease in their early stages.