 Good afternoon, and welcome to another episode of a likeable science here on Think Tech Hawaii. I'm your host Ethan Allen. Thanks for joining us today. Likeable science is all about how science is a vital, interesting, and dynamic part of everyone's life, and how we should all embrace science, be excited by science, and enjoy science. And with me today here in the Think Tech studio is Dr. Kate Peralt. Welcome, Kate. Kate is a professor of forensic science and chemistry at Shyamalan University, and has some very interesting things to talk about. Kate studies odors, right? Correct, yeah. And that's an intriguing thing. Before we get into the show, though, I want to do a little plug here for the upcoming Fall SACNAS conference. This is the biggest conference in the world for bringing unrepresented people into science. It's going to be here in Hawaii in the fall, right around Halloween, and the few days thereafter, it's a wonderful event. Everyone should know about it, encourage your students to attend, teachers should attend, faculty, great event. But now, so how did you get interested in studying odors? That's sort of an odd thing to study. Yeah, that's a question that I get asked quite a bit. In my undergraduate, when I was doing my bachelor's degree, I was really interested in forensic science. And to be a forensic scientist, you have to study lots of biology and chemistry. That's something I had a great affinity for from a pretty young age. When I got into my third year, I started a research internship in a laboratory. And at that point, I started working with decomposing remains, where we were looking at odors and other things related to how bodies decompose. And for me, that was it. I could see how biology and chemistry could really be used to help people in the real world. And that was really what sparked my interest. Wonderful. That's very important is that application of science to real world problems. Yeah, definitely. That's one of the things we try to emphasize in this show is that science isn't something that just lives in a laboratory for no reason. It actually has applications. Yeah. So I suspect a lot of people will sort of have an intuitive sense about what odors are, but they're really sort of a special class of things, right? Right. Okay. So it's good that you ask what an odor is. Some people use the words odor and scent or smell interchangeably. And they're not actually the same thing. So a scent or a smell, the way we use those words usually implies that there's a receiver and that there's some sort of interpretation of that odor. Biological receptor of it. Right. Exactly. Like what we have in our nose, right, our olfactory system. When we talk about an odor, though, that's actually a chemical property. So odors are a big mixture of different chemicals that are all combined together. And they kind of give us an odor picture when we smell them. But it's a chemical property and it exists whether or not we actually smell it. Okay. So you can have a machine that can detect an odor profile that we might not smell. Yeah, exactly. Some compounds that are present in odor we might not actually smell. And there might be some compounds that we smell really strongly that are not actually present in that high level. Okay. Excellent. And there's a particular class of these compounds that you talk about some called volatile organic compounds. Why are these sort of what are they why are they important? Right. So volatile organic compounds or we abbreviate them to VOCs, because as scientists, we like abbreviations. And VOCs are basically compounds that have what we call an appreciable vapor pressure. And all that really means in simple terms is that they prefer to be a gas rather than to be a liquid or a solid. So they like to exist in a gaseous state. And when a whole bunch of those chemicals in this gaseous state mixed together, that's what we call an odor. Okay. And being organic, they have to do typically with life forms, there are parts of life forms or exuded from life forms or whatever. So the VOCs are part and parcel of being being alive. Right, they're they're emitted from different sources that source doesn't necessarily have to be alive. Some of the things that we analyze are not living. But they are representation of the volatile part of whatever that target item is. Right. And so a lot of people don't seem to think much about smells except maybe when they smell something awful, right? Like a decomposing body. But obviously, we've built elaborate sensory systems for smell and then smell must have some odors must have some signal value, right? Otherwise, we wouldn't, we wouldn't have these elaborate sensory systems for them, right? Right, exactly. So in the laboratory, if anyone's ever watched CSI or forensic files, you might have heard of an instrument that's called a gas chromatography mass spectrometry or GCMS. This is usually the tool in the show, which is, you know, the thing that gives the magical answer, and it happens in a matter of seconds, and it's really exciting, right? And then that that gives an answer investigatory information. The way that this works to kind of bring it to an analogy, maybe it takes a mixture of things and separates them. So if you imagine say a group of people who walk into a room, let's say it's a party, there are a bunch of people in this party. Some people in the group that arrives, they're going to maybe not know anybody and they might be able to cross the room really quickly. Other people might know a lot of people in this party, and they're going to cross the room more slowly. Interact with more people. Interact with more people, exactly. They might have a different affinity for people. We talk about affinity in chemistry. And so the way that our chemicals, when they arrive in our instrument, the way that they have an affinity for the instrument makes the amount of time they spend in it be different. And so they separate. And when we separate things, when they're now in their individual, we can actually then identify what they are and quantify how much of each of them there is. Precisely what chemical this is and how much there is. Yeah, exactly. Excellent. So I guess my question had really been those are on the other end of things. These chemicals are often used for by living things to either to defend themselves, or in some cases to locate food or mates or dangerous things, right? Those are sort of being set of uses probably. There's actually also I guess a general orientation home use. Right. Yeah. So there's really two major things in forensic science that play a major role in the type of odors we analyze from remains or from human bodies. The first are insects. So insects are really good at picking up on these chemical cues and finding for them it's a nutrient source, right? So they're using those VOCs to find a body and they're really, really good at doing that. The other kind of biological sensor that we work with are scent detection canines. And so these canines are able to search for and locate human remains based on the volatiles that are released from them. They can actually orient and they do this really well too. And so we can use that in cases like missing persons or homicides or even in more large scale scenarios like a mass disaster, where we're actually trying to find a body. Okay. So this is this is great stuff. So it sounds like you you do a very interesting spectrum of work that part of your work is sort of out in the field, right? And part of it's in the laboratory, right? And your base at Shamanod's you have a field site nearby, nearby as part of the campus. Right. Yeah, we have a couple of really interesting facilities at Shamanod. This is showing our crime scene house that we have. This is a really great teaching tool. At this area, we can set up different mock crime scenes. And then we also have a decomposition field site as well that we use to decompose pig carcasses. So we use pig carcasses as analogs for human decomposition. And we are able to collect volatiles from them. Okay, right, because there are all kinds of interesting ethical issues about using human remains, right? Right, exactly. Right. And logistical issues as well. Yes. And the when you are out in the field, you you need then to capture these odors right to begin your analysis. And I think you have a picture of right. Yeah, okay, so I can describe. So basically, when we have pig carcasses that are decomposing, we place a large stainless steel hood over top of them. So that's this box that you see. It's actually open on the bottom. So it goes over whatever we're collecting odor from that could be a pig carcass, it could be something else, right? Could just be soil that we're interested in. On top of that stainless steel hood, you'll see there's a tube actually kind of sticking out of the top of it. It's about four inches long stainless steel on the inside of that tube is something called a sorbent. The way I usually describe sorbents is kind of like what's inside of a Brita cartridge if you're filtering water. So when you're when you have Brita filter and you're pouring water through it, the water goes through and the chemicals that you're trying to attract stick to that cartridge and the water flows. We do pretty much the same thing, but we pump air through this smaller tube and the volatiles that are in the air then get trapped on the inside of the tube on this sorbent and we can take that tube back to the lab and analyze it. Three or GC amounts. Correct, yeah. So we take the tube to the laboratory, we put it in an attachment that basically heats it under a flow of gas and the heat actually removes all of the volatiles from the sorbent and we can inject it onto our instrument. Yeah, all right. Well, that's great. So that's a really nice sort of spectrum of activities and that you do from very sort of rough and tumble stuff out in the woods to very sophisticated laboratory based analysis. Yeah, I really like that aspect of it because especially with the background that I had in my education, I got to do a lot of field work and I realized science doesn't always happen in the laboratory. You got to get out and do the work in the field sometimes and that's something that I personally really enjoy. Right, that's again something a lot of people don't realize is, you know, in many cases actually a vital part is to, you know, go out there and find that, find those samples that you need that are going to help determine was there a person here, is there a person buried here or whatever. Right. Exactly, exactly. So that's just amazing stuff then. So if we, if we use odors, we smell odors, I mean, does it have biological significance to our lives? In terms of safety, for example, yeah, so there is, we don't do a whole lot of work in this, but there is a lot of environmental monitoring which is done. For example, a lot of building materials give off these VOCs as well and that can have implications in terms of health. If you've ever heard of something called sick building syndrome, that's that has VOC background to it as well. So we can use the same sort of techniques that we have in forensic science. In fact, a lot of those are adopted from the field of environmental monitoring. Okay. And so you've talked in our earlier conversations a little bit about this GCMS machine that you use and it's a very cutting-edge machine. So can you tell us in simple terms what sort of spiffy and cool and neat about it? What does it do better than older machines? Great. Okay. So GCMS is something that's been around for a really long time. It's really a gold standard in most laboratories that you can think of, medical laboratories, environmental laboratories, things like that, forensic science as well. What we actually use, the instrument you see here, is something called comprehensive two-dimensional gas chromatography. So this is kind of like the new age of GC. And what this allows us to do is actually take the compounds and separate them twice, hence the name two-dimensional. So when we could maybe separate, say, 60 compounds in an odor before, now we have the ability to separate maybe 600 compounds. So we pretty much get an order of magnitude increase in what we're able to separate. And that has really important implications because if you can separate more, then you can identify each of these compounds better and quantify them more accurately. Okay. So and this is, again, something I suspect a lot of people don't understand, is that these sort of chemical soup that you're analyzing is incredibly rich in terms of it has hundreds, if not thousands of different chemicals actually within it. Yes. And so the more fine you can pull this all apart, the more accurately you can determine what's really in there, where it came from, how much it came from, what? Yeah, one of the things that I didn't realize when I got into the field is actually how complex of an analytical problem this odor actually is. We have thousands of different chemicals, not all of them might be important, some of them may be important, but we need to separate the ones that are important from the ones that are not. And they also exist in a variety of different chemical classes. So they all have different behaviors. So you're dealing with a really complex analytical problem. You also have some that are really high in abundance and some that are really low in abundance. And analytically that's also a big challenge to get a technique that allows you to quantify things at that different level. So lots of challenges that we're up against and that's why this new technology that we've brought to Shamanad gives us a big advantage in what we do. Excellent. We're going to explore that a little more deeply when we come back. Right now we're going to have to take a brief break. Kate Peralta is here from Shamanad University talking about odors with me. I'm your host Ethan Allen here on Likeable Science and we'll be back in one minute. Hey loha. My name is Andrew Lanning. I'm the host of Security Matters Hawaii airing every Wednesday here on Think Tech Hawaii live from the studios. I'll bring you guests. I'll bring you information about the things in security that matter to keeping you safe, your co-workers safe, your family safe, to keep our community safe. We want to teach you about those things in our industry that you know may be a little outside of your experience. So please join me because security matters. Aloha. Hi my name is Amy Ortega Anderson inviting you to join us every Tuesday here on Pinoy Power Hawaii with Think Tech Hawaii. We come to your home at 12 noon every Tuesday. We invite you to listen, watch for our mission of empowerment. We aim to enrich, enlighten, educate, entertain and we hope to empower. Again, maraming, salamat po, mabuhay, and aloha. And welcome back to likable science here on Think Tech Hawaii. I'm your host Ethan Allen. With me today in the Think Tech studios is Dr. Keith Peralt. Welcome we end Kate. We're talking about odors and Kate's a forensic chemist I guess you call it yourself. And so looks at the chemistry of decaying stuff and that's very interesting because all these decaying things are putting out all kinds of different chemicals but there's a lot of other of these VOCs, volatile organic compounds around too that that are emitted from as you were talking about paints or carpets or building materials but also from explosives right? Most explosives actually emit some relatively low levels of these VOCs so I was reading a while ago about somebody who had figured out that certain wasps can detect these very low levels some of these explosives and they have essentially trained these wasps to make some reaction either wasps fly left or fly right or up or down or something. Some sort of behavioral. Right and so they can build a very simple detector basically just a can with the wasps in it and they run air through it and if the wasps do a certain thing I know that what they've got in front of them is dangerous. Yes. So it's a sort of biological version of your of your GCMS machine right? Right exactly yeah and there's a lot of interest in developing these sort of like handheld tools that can be brought to certain locations critical locations like border crossings airports for example where you can have something that's portable that's easy to use that doesn't require a lot of expertise or training but that provides that kind of yes or no answer. Right. Yeah in that case it's a very specific one these wasps won't particularly react to anything else I don't care if you've got a dead body in there right you know they're not going to care and they're not going to react it's it's very specific sorts of things whether it's your big fancy GCMS can tell you any of these things all of them. Right the the big instrumentation that we use in the laboratories we use to gain information right and that information can then serve to develop cheaper faster easier tools that we can use to detect certain things. Right because it you can then develop sensors that are particularly tuned into some one of those compounds or two or a sweet amount or something yeah and then that becomes more sort of like what what some animals are doing right when they're when they're very tuned into very specific molecules. Yeah. A classic case being the insect sex pheromones right that the males are tuned into this one suite of molecules. Yeah. And can detect them incredibly low concentrations and hone in on them to find their opportunity to make. Right. And there's a lot of interest as well in developing these handheld tools for things like mass disasters where you might have sent detection canines to be able to do some of the work. But those are living beings and they need a rest and there are only so many of them. So if we can develop sensors that can at least help in a complementary manner then that can really alleviate some of the workload in some of those really important cases. Right so this ties in very much then to some of the developments in material science as they're getting better and better at building or molecular building at the molecular level. Right as you as you provide them with analyses of certain kinds of chemicals they can say oh well we could build this neatly trap that and your conformational change or electrical change or whatever. Right exactly we provide the targets for them to be able to then develop those sensors based off of. Yeah excellent excellent that's great and this is I mean people don't I think a lot of people don't realize how important and how driven animals are by these by these particular molecules that the classic case was when I was doing a post doctoral fellowship in Texas we were looking at the sex lives of reptiles and the females put out a sex attractant pheromone as soon as they emerge which if you wipe that off the back of a female you can put it on a paper towel and present that paper towel to the males and they will react to that paper towel as if it's a female snake because it's an attractive female snake they will court it vigorously they will they will chin rub on it they will get on huff and start writhing around trying there to do their best to mate with it even though it bears no relationship other than chemically attractive female it's very very powerful stuff. Right I think that the biology of a lot of these animals and how they react to some of these chemicals is so interesting and I think as chemists it's really our job to try to be as good as they are actually and in some ways we're approaching that but I think using a lot of these animal models and the information we can get from those systems provides us with a lot for our field as well. Right yeah and there's there are a huge array now of studies going on that they've started using sometimes predator scent to help move prey animals keep prey animals out of areas basically where they want the vegetation to regrow or something if they're herbivores and they think that a leopard or whatever is around they won't they won't hang out there they won't eat the plants. Yeah there's a lot of that kind of work also being done with pests as well if you know which chemicals are an attractant or a repellent for a certain pest then you can place those things in different areas to move them where you want them right away from areas where you don't want them. And it's incredibly sophisticated chemistry right I mean right and another classic case that I recall is the there's a spider that produces rather than a regular web a long one long thread with a sticky glob on the bottom of it and the sticky glob puts out actually a moth sex attractant pheromone. Oh okay. Spider has actually learned to produce or learned of all to produce that particular chemical. The only thing the spider eats is male moths of one particular species basically. Wow that's fascinating. But again it's it's taking same kind of idea of picking up picking up odor traces out of an airstream basically. Yep exactly. So yeah this is incredible stuff. So other than those obscure uses of the animals do we've talked about sort of forensic and law enforcement people wanting to know about dead bodies that we mentioned briefly. Border agents wanting to know about explosives. But there's probably a lot more uses that people don't think about right people may want to use these. Yeah that's definitely true there are a lot of different industries that use odor analysis to get information about whatever it is they're analyzing. A good example is the food industry. Odor analysis is used to monitor quality of food products. Meat spoilage for example is a good one that people might not be aware of. So you can use the odor that's coming from a package of meat to see if it's spoiled or not. There's also a lot of work being done with odors to look at food adulteration. So for example if you have some you know really pure extra virgin olive oil that claims to come from a particular region is it adulterated with some canola oil or something like that. So there's a lot of different ways that we can use this type of analysis in other ways that benefit people too. We're actually starting to work on a project here in Hawaii looking at Kava analysis. So we're looking at the aroma that comes from the Kava root and this is a beverage which is consumed in the Pacific Islands. There is a lot of interest in potentially using it as an anti-anxiety treatment as a medicine. And so we're starting to look at the aroma from it so that we can kind of establish a baseline of what that aroma looks like and then use that to be able to monitor you know where these products are coming from and hopefully ensure that there's good quality in them. So yeah you'll be better able to extract what you want from the Kava root and get rid of the stuff you don't want so you can make a more palatable beverage. Sure yeah. This Kava is pretty awful tasting. I don't mind the tasting. But same kind of thing yeah you can see this with for instance coffee you might be able with your analysis to be able to tell is this really cone of coffee as its label is claiming right? Because cone of coffee presumably is chemically different from not cone of coffee. Absolutely it's interesting that you bring that up because last year with my instrumental analysis class that's exactly what we did we analyzed a variety of different coffees some which were 100% Kona or claim at least on the label to be some which were blends of Kona and something else and then some which were completely not Kona coffee. And so we looked at the aroma profiles from those different samples and we try to extract what is associated with the different brands. I mean did you find what anything are people telling the truth? It's hard to really put a blanket statement on it because we analyzed maybe six different coffees and I think you'd have to do a much bigger project than that to say one way or another but there are definitely differences between them and even the Kona coffee itself that we analyzed to pure 100% Kona coffees and they actually look different from one another to chemically so that probably has a lot to do with the specific region there. The land that they're being grown on, the soil how much water they get stuff like that. They call it wine terroir, right? Yeah, terroir, exactly. Yeah, it has to do with the chalkiness of the soil the organic content of the soil, how much rain they've gotten that particular year. Yeah, so we can maybe use aroma to look at the geographical region even. That might be something of interest too, so. That's amazing. So if you had to give some brief advice to students who might want to pursue this kind of area, what advice in 30 seconds or so would you give them? Oh, that's a good one. I think that having a really strong foundation in biology and chemistry is really essential for this field. You have to really have a passion for it. I think communication is really important being able to talk about your science. So having a passion for it really helps you to be able to do that, but find something that interests you that you're never going to get bored by. I feel like with my area of research, I have tons of projects to keep me busy until the end of time and that makes me really happy. Excellent, excellent. Well, this is great and I think that sounded nice. I think it may be a good scientist. You really have to be excited, passionate about what it is you do. So before we wrap up, I want to ask you one completely off-the-wall question now. So, I have a lot of thought to this. If you had the choice of two superpowers, you could either fly or be invisible, which do you choose and why? Oh, that's a good one. Fly or be invisible? I think I'd rather fly because actually we were talking about this earlier that I feel like I haven't seen enough of the world yet and I think there's a lot of really cool science being done all over the world and I think having the ability to fly and really be very mobile and experience science all over would be great. Cool, excellent. Thank you so much. It's been really wonderful to have you here. Kate Perrault from the Shalmanad University of Honolulu as a professor of forensic chemistry and has been studying how things decay and has been here talking with us about odors and I thank you very much. You've enlightened me a great deal and I'm sure in the one you're talking about. And this is what a great conversation. I would say it's been a stinky conversation. But it's great. It's wonderful to learn about this and to hear about what you do. I wish you much success in your studies investigations and perhaps we'll come back later on and talk some more about it. Absolutely, that would be great. Thank you so much for being here. Thank you. And thank you for watching Likeable Science here on Think Tech Hawaii. Until next week, I'm your host Ethan Allen.