Published: October 04, 2018
Forensic Science Major Uses Lasers, Plasma in Mass Spec Research
Breaking things in Cass lab 201 happens on a nearly weekly basis for Gaston Merideth II ’18. The forensic science major said it’s all part of experimentation.
“Research teaches a lot of good skills, like problem-solving, thinking and patience, because things break a lot and you have to sit there and wait and wait for it to get fixed, wait for the part to come in,” said Merideth. “I like research, because you learn a lot. There's no given answer to the problems. When I come in to do research, we’re trying to discover new things. We don’t know what we’re looking for.”
Merideth has been working since his first year at UT with Kenyon Evans-Nguyen, associate professor of chemistry, on finding ways to analyze forensic evidence quickly while in the field.
Mass spectrometry is the most common technology used for forensic chemistry evidence analysis, however preparing samples for the mass spectrometer can be a long, arduous process.
“Our research is focused on creating innovative methods for easy sample preparation for the mass spectrometer,” Merideth said. “To do this, the research is focused on the dynamics of plasmas and lasers that provide near instantaneous sample preparation for the mass spectrometer.”
The samples that are fed into the mass spectrometer traditionally have to be processed in such a way that they form a clear liquid in order for the machine’s ion source (which is like a lens) to read the sample. Traditional methods involve a process similar to the following: Hunt around at the crime scene for items that can be sampled, take them back to the lab to rinse with solvents, filter and prepare them until they become a beautiful clear liquid that is then pumped into the mass spectrometer, which converts it to ions that are read by the scientists, confirming or negating the presence of whatever substance they were looking for at the crime scene, such as explosives residue, blood or drugs.
In 2005, researchers started discovering ion sources that would read solid samples. While there are lots of other universities and companies working on ways to refine this process for organic materials, for applications in things like real-time medical results during surgeries or the next airport screening technique, Merideth and Evans-Nguyen are focused on ambient elemental analysis — using the mass spectrometer’s commercial ion source to read elements like zinc, copper and iron from solid or more opaque samples.
“We would love to be able to do it quickly in the lab. A lot of other people are working on a portable mass spectrometer that you’d have in your crime scene van that has a source on it that you’re using at the scene,” Evans-Nguyen said. “Oh look at this chunk of metal — and you can immediately see that it’s useful, it has explosives on it, and you package it up and take it to the lab as opposed to making your best guess.”
Merideth wants to go into law enforcement when he graduates in December. He chose forensic science because he loves learning about science. He also thought it’d be good to have another career option if things didn’t work out with law enforcement.
“It’s been really good to learn more about my field, about what's going on in forensic science, what techniques are new, where’s the money at in the field,” said Merideth, who presented his research at the American Society of Mass Spectrometry in 2017. It really helped me understand what this degree is about, and if I ever got a job in forensics, what it would entail if I wanted to go into research.”
That being said, his research experience will serve him well in criminology.
“First, you have to be patient, and that’s really important with dealing with people,” he said. “Second, it taught me a lot of thinking through problems. One of the main things we have to do is troubleshoot whenever something goes down and start all the way from the beginning and work our way until we figure out where the problem is. That is applicable to law enforcement. I need to be able to go into situations being meticulous about every detail.”
Merideth is finishing his last semester at UT training the next student to take his place in the lab. He’s changed since his first year in the lab and will be graduating with far more confidence than he started. That transformation is one of the best rewards for Evans-Nguyen.
“After they’ve failed and failed and succeeded and seen how that works, those nuggets of success you get are remarkable. And once they taste that, it’s a huge boost to their confidence and it translates to everything,” he said, including employment after graduation.
Evans-Nguyen said he’s received feedback from employers impressed with his students’ ability not to panic when they get in the lab but instead go up to the unfamiliar technology “and they just sort of wrestle with it until they get it. I think it's a learned skill. It’s something you practice. They do it here in a training situation, then after a while they just start doing things on their own.”