Good afternoon.
Welcome to the Department of Homeland Security
Science & Technology Directorates Tech Talk.
So the Science and Technology Directorate
for those of you who have not tuned in before,
is the research and development arm
for the Department of Homeland Security,
helping to support the mission to protect
the nation across all of our
operational components, also supporting
the nation's first responders and our
critical infrastructure, and it's quite
a large task. Today, what we're going to be
talking about in our Tech Talk series
is we're gonna talk about trace detection
explosives trace detection.
With us today is Dr. Laura Parker, who's
a chemist with our explosives division
here in the Science & Technology Directorate.
Good afternoon and welcome, welcome Laura.
So, I guess we want to start this off to get a
real good understanding of what the heck
is trace detection?
So explosive trace detection,
is screening for microscopic amounts of materials,
explosive materials, and the interest
is peoples baggage, people, cargo.
And there are multiple types of technologies
that can be used to detect trace explosives.
Today I am going to focus on explosive trace
detectors, as we call them specifically,
and those you can detect particles in vapor.
Wow! So when we say particles how small
are we talking about when we're talking about trace?
What is the smallest trace that can be detected?
Without giving away obviously, secrets.
So, with the trace detection we look at the
amounts found in a fingerprint.
So very small amounts you can't
really see them very well with your eye.
We do not focus on what we call bulk amounts,
Which you can, you know, more easily see with the eye.
So the trace detection is just looking
for those, those minute particles
that might be left behind.
Sometimes we say residues, particles or residues.
Excellent. So let me ask this question.
Obviously you know tracing, detecting bulk
explosives or larger quantities of explosives
is obviously important. But why is it
important to be able to trace, to detect
these trace amounts of explosives?
So we look for trace, because that if you
find trace amounts of explosives,
that's an indicator, you know, we're looking
for indicators that we need to look further
or that you know there's something to
really be concerned about.
That leads to maybe using other technologies as well.
Now I know most people see this kind of
thing at airports right? And that's where
I think most people are familiar with it.
So where does this kind of trace detection
take place? Is it only at airports or
other kinds of environments as well?
Yes, the traveling public really sees
the explosive trace detectors that,
that I'm focusing on today at airports.
but they're also used anywhere that
the Homeland Security operates.
could be at borders, people at large crowd events, or their their bags.
Things like that. So they they can be used
in many different environments.
So any potentially, any checkpoint type of environment?
Yes.
So, when people are going through
these trace detectors, going through a screening process,
what is actually is actually happening
when the officers are screening for traces
of explosive material? What's the process?
What people notice first is the officer
will have, usually, what we call a swab
which is a piece of fabric and they'll
either have it in a wand, that's so the
fabric will be attached to the end of a wand
or in the officers hand and they do just
swab over possessions or people's hands
and then they insert it into the
explosive trace detector, and in that process
the swabs heated up, material is vaporized
and goes into the machine and then
that's where the detection happens,
inside of that instrument and then
the officer gets an outcome.
You know, whether an explosive is present or not.
So how does that actually work?
Currently the systems are based on
eye mobility spectrometry and that's a
technology, analytical chemistry technique
that's been around a long time and that
pretty much looks at the size and shape
of molecules, compares it to a library
of many chemicals and then gives
it gives an outcome.
So is the basic science still kind of the same
in understanding these chemical signatures?
You mean, just the way, so for trace
explosives detection we do want to know
what the chemicals are. Explosives are just a type of chemical.
So this immobility spectrometry is a
chemical detector essentially.
It's just been tuned for, well, chemicals of
interest, such as explosives explosives.
Got it. What we call energetics?
In the conventional explosives world,
it's energetic materials.
Okay, got it. So can you give us a little bit
of an overview of some of the different
kinds of technologies that S&T is developing
in this trace detection area?
So as I said before, I have focused the program
on explosive trace detectors that are
based on immobility spectrometry.
There's a lot of interest in using mass
spectrometry, which is an analytical
again, an analytical chemistry tool that's
commonly used in laboratories across the
country and around the world for
identifying chemicals, but it's kind of,
it's considered a gold standard in the
laboratory world. But to shrink it
down to be used in the field is a bit of a
challenge. So the immobility spectrometry
also known as IMS technology was fielded
pretty readily years ago and mass spec
working on trying to feel that technology for DHS.
We also look at sampling.
It's pretty difficult, if you can't see the samples,
you have to find them somehow.
sampling is a big challenge in trace detection.
I do work a lot in more advanced sampling
methods, you know, how to be more efficient
with sampling. Also we're trying to move
away from having to swab everything
with these pieces of fabric to what we
call non-contact sampling, where we
wouldn't have to touch people or their bags.
But that has challenges as well.
You can use air to try to move particles
around and collect them. There can be
laser techniques that you can use
to find particles as well.
Yeah, so but with lasers I just want to
emphasize we're always concerned about
safety and eye safety is a component
of that type of technology.
That makes sense really exciting.
There different ways I never really
thought of it for the sample collection
aspect of this being just as important,
if not even more important than
the ability to analyze the sample itself.
So, you were talking about how getting
it down into a small enough size to
be able to use in a practical environment.
But also, I would imagine, it's speed has something to do with it.
How long does it take for one of these analyzers to actually work?
So seconds, for the analysis itself.
There are requirements when we're
working on new technologies to keep
the detection cycle very fast.
But it also. the you know there's people involved
in swabbing, that's another reason
we like to do more non-contact.
It does take the operator some time
to swab and insert into the instruments.
The whole cycle though is seconds because
we really keep in mind that people don't
want to wait in airports or even, you know
the end users and cargo facilities
and groups like that, they are
trying to really screen it very quickly.
There is a training element to all of this as well isn't there?
We have spent a significant effort on
looking at efficient ways of swabbing.
When I first started in this program
I didn't realize how much effort goes
into what kinds of materials the swabs
should be and it's, there are different types
of fabric and just getting the right
right pressure as you swab on the surface,
takes more than you would think.
We produced a pressure-sensitive wand
that we're looking at transitioning for
training purposes. I mean you wouldn't
necessarily see it at airports. But with
a red light green light it helps the to
train the end-users how much pressure
they really need to be able to collect,
collect a sample efficiently.
That's smart, that's a smart training device.
So, I wanted to to remind folks out there
that you can please submit questions and
we did just get questions from out there.
So, the first question was how long does
detection usually take? You actually kinda
hit on that and in a matter of seconds.
So we'll go to the second part of that question.
Is what happens if it comes up with a
comes up with a positive result for explosive material?
So if you're in an airport, there are certain
procedures that the the TSO's follow,
the transportation security officer.
And again it can, it depends, usually it's
they swab you again. To try to make sure...
Get some validation.
Yeah, to validate and then depending
on how that goes a lot of times...
Guess there's different operational
protocols for the response side of this.
but our focus is on the actual
detection capabilities itself.
Yeah there's a lot of, we look at the
requirements for how to validate the
the instruments as well, and make sure
that they're operating efficiently.
So while we're kind of on that topic,
let's talk a little bit about, you talk
about validating what the machine is seeing.
What can you tell me about how we kind of
avoid false positives or that kind of thing
in your validation process?
So the way the technology operates,
it is a specific, their IMS or the mass spec
that I mentioned, or even some of the other
technologies. I'm not as focused on today with them.
They really do identify the chemicals
present and explosives are just a
type of chemical essentially.
So that, there's a lot of work that goes into
making sure that you can identify them properly.
There are interference at times with
ya know, just the environment that these
are used in. So work goes into that as well.
Everything from the detection equipment
itself to algorithms and the analysis for the output.
And thus the potential for retest and that kind of stuff.
So, you know, we're talking explosives.
I have to ask this goofy question.
Is this dangerous work?
Because it's trace amounts, these are
very small amounts that don't pose a
threat to people. So the instruments
themselves are also analytical instruments
that have been around a long time.
They're not, they're very safe.
So, I'll remind folks out there please do
submit questions. But I've got some more,
and I'd like to know, is what's the hardest
thing about trace detection? What makes it such a challenge?
It's the sampling is quite a challenge.
You know making sure that you get sample.
You know, you can have the best detector
in the world, and very sensitive, but if you
don't have a sample, then you're not going to detect it.
So, there's a lot of research that goes
into making sure we're, you know,
collecting efficiently. As I mentioned, the right
now we use the manually swabbing.
That's a lot of workers to do that and we're
So the interest in moving towards non-contact
sampling would be, you might
also reduce some of the variables of
having to directly swab. Of course you
may add other variables but there's a
lot of interest in new ways to sample.
I guess it's really interesting to understand
how we're trying to advance the technology.
I mean obviously we want to keep
things fast, we wanted as less invasive
as possible, but yes, we all we also want
to have that accuracy and that assurance
that what we're finding is correct
and that we have the ability to detect
when there is a problem.
Thank you folks. It looks like we are
getting some questions. And one question is,
What does secondary screening look like?
Now this is considered secondary
screening not primary screening, right, normally?
Yes, so should I explain what that?
Might be a good idea to kind of explain
it and then we'll address the question itself.
But so where in the screening
process is trace detection used mostly?
Yeah, so for the traveling public,
they would experience the explosive
trace detection piece, when you send
send your bag through at a checkpoint
and you walk through, if there's an alarm
on the bag ,they typically take the bag
the bag off and they will swab it and
that is the trace explosive detection
secondary screening layer. So that's what
they mean by secondary screening.
You don't typically see them swabbing
every single, you know, the workers
swabbing everything. That would be primary,
where they, where you always use
the systems. So within the next three to
five years there's a lot of interest in
having expandable libraries. So being
able to see a lot more chemicals of
interest, I'll call them. And the lighter
systems, systems that are, don't
use as many consumables. So I'm looking
at the three to five years from now
I think I answered that. but again there's
there's always a driver that whatever
we're deploying, it gets people through
quickly, you know any changes have to be verified.
Right, okay, interesting.
Another question and thank you folks
for submitting this. Can you speak to the use of
infrared lasers for standoff detection?
There's a lot of interest with the
advancement of quantum cascade lasers
and the whole area of optical trace detection.
I didn't talk about that as much.
My program itself isn't as focused
in that area but that's a very important
technology area that we could really see
some advances over the next, you know,
I would say at least five years.
So for standoff trace detection there's
been a lot of interest at whatever, well,
stand off is a term that means different
things to different people and some
environment standoff could be fifty
meters in our environment it could be
you know a meter.
The distance really can affect how well
you can detect these chemical... traces.
Yeah, and the traces again, you have to
know where to look for these fingerprint
size amounts of material. But there's
definitely a lot of promise in the trace optical area.
No. Really, interesting.
So since we're talking about these
advances in technology, are there any
success stories that you can share with us
or recent technology transitions that have happened?
The movement towards having a mass
spectrometer as the detection engine has
been a big focus of my program, where the
hope for that is that you'll be able
able to get a broader library of chemicals
of interest that you're looking for.
But it has to be in a smaller package
than a typical mass spec.
The program I have, we have several
prototypes when we fund people, performers.
We typically want prototypes that we
send for developmental tests and evaluations.
And I have several of those kinds
of prototypes that are gonna be going
detainee, we call it. Pretty soon, to validate
and assess how well they're operating.
And then the pressure-sensitive wands,
I had mentioned, previously, that's a tool that
can be used for training, which isn't
you know, I like to say, everyone's always
interested in new detectors because
they're very wow and whiz-bang.
Making sure you have tools and ways to
operate them properly. We also work on that as well.
Yeah, well like you mentioned earlier
the sampling is just as important as
the detection capability and having
these new pressure sensitive wands
for training purposes really comes in
I think it sounds brilliant, actually,
to be able to understand how to capture
those, capture those samples correctly.
We talked a lot about explosives
and you say, these really are basically
chemical detectors. So I know our focus
has been on explosives. Can they detect other stuff as well?
It's a chemical detector, they definitely can
detect drugs as well, chemical warfare
agents it turns out, there's a lot of
historical development behind that.
A wide range of chemicals, especially
in the environment that sort
of field of looking at how to detect
chemicals in the environment. We work
with a lot of partners too and they're
from all different fields of interest
from like I said environmental chemistry
to you know kind of the traditional
explosives field. And you know, people
that work on standards and how to test
equipment. So it takes a takes a village.
You know, actually takes a big field
to develop these types of systems.
It sounds, it sounds really exciting actually.
How did you get into this line of work?
I'm a PhD chemist by training, and when I joined
Department Homeland Security Science & Technology Directorate
years ago they had this program and it matched my skill-set
really well to be able to work with
other chemists, and as I said, there are
more than just chemists at work on these
kinds of equipment. But the history of
explosive trace detectors is more in the
analytical chemistry side, and since I'm
a chemist it was a good match and it's
you know, a lot of interesting pieces to
it the materials the even the algorithm
development, you know, really you have to
bring it all together. As a program manager,
I like that aspect, as well.
Sounds like a very unique way
and rewarding way to apply your skills
into a very practical and useful mission.
So thank you for your efforts in that.
So, we're getting tight on time.
So if there are any more questions from
the field. please feel free to submit them.
We have, this will be posted on our
Facebook page so that you can view it again later on.
If you didn't have time to catch all the answers,
you can submit additional questions,
we will get back to you on those even after this is over.
So feel free to be able to submit your questions.
As we get ready to wrap this up today,
is there anything that you'd like to remind
folks about your program, maybe you know,
if there's one thing people should know
about trace detection, what is that one thing
you want them to go home with today?
[Long Pause]
That's a good question.
To keep in mind that, you know, we're at
DHS S&T, we're always trying to find
efficient and cost-effective ways to
screen, you know, at airports or ports of entry,
people at large crowd events, whatever
it is and make sure everybody is
you know, kept safe and the venue is secure.
Excellent. Well thank you so much Dr. Parker,
really appreciate you taking the time
to be with us today.
And thank you all for joining us.
Please keep tracking us, watch us on
Facebook and on Twitter at DHS SciTech, S-C-I-T-E-C-H.
And we will see you next time. Thanks for joining us.