From PittconReviewed by Danielle Ellis, B.Sc.Jul 1 2024

In this interview conducted at Pittcon 2024 in San Diego, we spoke to Professor Arian van Asten about advancements in the chemical analysis of drugs and explosives using portable NIR spectroscopy and its significant impact on improving on-scene investigation methods for law enforcement agencies.

My name is Arian van Asten. I am a professor of forensic analytical chemistry at the Van 't Hoff Institute of Molecular Sciences of the University of Amsterdam. Before that, I worked for a long time at the Netherlands Forensic Institute.

I have a PhD in analytical chemistry and a passion for forensic science. I am involved in many different projects focusing on a wide array of evidence materials and analysis methods, but my special interest is in the analysis of drugs and explosives. What makes them special is that these chemicals are directly related to certain types of crimes.

Starting with illicit drugs, the US is in the midst of the opioid crisis. This translates to forensic experts seeing an increasing number of cases. The caseload is very high, and the chemical complexity of the samples requiring analysis has also increased. It is more difficult to analyze them correctly.

With respect to explosives, this is a challenging area because of the chemical diversity that is encountered. You have organic and inorganic materials, so typically, one single analytical technique does not suffice in a given case.

In addition, there are cases in which intact explosives are present, which we call pre-explosion cases, and cases after an explosion. These two settings yield completely different samples to analyze.

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The work that I presented at the Pittcon Conference allows people to conduct chemical analysis in the field using portable technologies that do not require high-end laboratory conditions.

This is focused explicitly on rapid chemical identification of drugs and explosives with operators who do not need a chemistry background. I try to advance forensic analytical chemistryin this way.

As a forensic or analytical chemistry expert, I think the challenge is to create a methodology that allows non-experts to do complex chemical analyses themselves in a simple and error-free manner. If measurements fail because controlling the instrument is too complicated, then we have to make it simpler! This would ultimately allow law enforcement professionals to identify drugs and explosives robustly and instantly.

There are several options or routes that you can consider, such as mobile mass spectrometry, electrochemistry, and colorimetric reactions. Then, there are several spectroscopic methods to consider: Raman, infrared, and near-infrared. We chose near spectroscopy, as it lends itself very well to miniaturization. You can have very small, almost pocket-sized, near-infrared spectrometers, and they are extremely rapid. Using the technology we work with, you record a reflectance spectrum in a few seconds.

When people talk about rapid analysis, they sometimes introduce methods that take a few minutes. If you talk to professionals who operate within law enforcement or customs, a few minutes on the scene doing a measurement can feel like a lifetime. That makes near spectroscopy very attractive. Within 10 to 20 seconds, I can do multiple measurements on the same sample.

For illicit drugs, for example, the first step in the field is often a colorimetric reaction. This is challenging because people in the field have to add liquids to a sample to observe color, and they are not necessarily trained to do so.

We use reflectance sensors, where people simply place a glass vialwith a small amount of powder directly on the sensor, and then press scan. There is no sample preparation, no complex instructions. This is a very convenient process both in the field and in a laboratory situation where you are carrying out high-volume screening.

Pittcon Thought Leader: Arian Van AstenPlay

Credit is due here to Dr. Henk-Jan Ramaker from TIPb. He did and does a lot of the model development and the chemometrics (advanced data analysis).

This is also where one of the technique's challenges comes in. Imagine you are in a forensic setting, and you have a sample with an unknown composition. You have an idea that it could contain explosives or illicit drugs, depending on the context of the case, but you are not sure. The sample is also not pure.

A typical street sample of a drug can contain several other substances in addition to the psychoactive substance of interest. This includes adulterants, diluents, or tableting agents. When taking a measurement, you will get a composite signal with spectral features of all these components. So here, we need data science to help us decipher the complex signal and tell us what compounds are present and at what level.

You can take a machine learning approach, but that typically requires huge amounts of data. We can measure thousands of street samples, for which we have used other techniques like GC-MS to determine the composition. We use that knowledge to look for similar signals if we have an unknown and suggest its composition.

What Dr. Ramaker has developed is much more elegant. He takes pure compound spectra of all the known possible constituents in a sample for a given type of drug. With this limited set of spectral reference data, he subsequently 'explains' the observed signal.This is much faster and requires less reference data for a functional model. You, for instance, only need the NIR spectra for 10-15 pure compounds to fit all cocaine street formulations.

I think both are true. We have more analytical capability to look at very low levels of substances within samples and chemically understand what is going on.

Chemical profiling is a different field that I am involved in. Here, we look at how materials are degrading and what kind of raw materials are used. We are interested in impurities and what they tell us about how the material was made or transported. You cannot typically do that with portable spectroscopy. The technique is not sensitive enough. Compounds need to be present at 5-10 wt% to be 'noticed'.

It is also true that the chemical complexity of illicit drug case samples has increased considerably. There are two reasons for that.

First of all, because many countries work with lists of banned substances in their illicit drug legal framework, we have seen 'creative' criminals producing so-called new psychoactive substances (NPS). These designer drugs look and function very similar to their banned analogs but are not listed and, therefore, do not fall under the illicit drug law. Selling such a product is consequently not an illicit drug crime.

Governments tend to react when they see such new materials entering the illicit drug market. They take legal action to place the new compound on the list of banned substances. But that fuels a rat race in which the criminal makes another variant when the ban is successful. We have seen a rise in what we call designer drugs in many European markets. Meanwhile, there is an additionalchallenge here in the US where the ongoing opioid crisis is leading to drug street samples that contain multiple fentanyl analogs at relatively low levels in the presence of cocaine or heroin.

I think there is. The forensic science domain is open, but it is also a somewhat complex situation. We are scientists, so we wou
ld like to explore new methods, develop them, and share them to contribute to a safe and just society. But at the same time, there is always the risk that this information falls into the wrong hands. This is especially important when you investigate how to make explosives or how to characterize drugs of abuse.

Additionally, forensic science is typically a very international, open environment where people are eager to share, whereas criminal justice is typically more closed, domestic, and local. This makes it for instance difficult and rare to bring in foreign forensic experts to report and testify in a case. This is also understandable, crime is a sensitive and typically a national affair with local victims and perpetrators.

There are a couple of problems here. First of all, when you transition from science and innovation to something used in forensic practice and being presented as forensic evidence in court, you need to be very strict with respect to quality. You need validation studies and accredited methods. You have accreditation bodies that come and check to make sure that 'you say what you do and do what you say.'

So you need to make that new method fit for purpose. You would have to show, quite vigorously, that you know the error rates, you know when things go wrong, you know how to spot an error and how to improve. This is very important because once that evidence is in court, it can have a lot of impact, especially when drugs or explosives are involved. You need it to be free of error.

Of course, where work is done, errors are made; this is inevitable. But in a forensic setting, you need to show that you have minimized and mitigated potential errors and that you have a system in place to spot errors, correct them, and prevent them from happening in the future. Forensic evidence can make a lot of difference to the people involved, including suspects, victims, and family members, and therefore, must be of superior quality.

However, there is also the interesting question of when a forensic investigation is good enough. When is there enough selectivity to say that, with a portable technique, you can do a measurement in seconds and also present the findings with confidence in court? Here, as a forensic scientist from academia, you can run into some conservatism and resistance. People tend to rely on what they trust and have been using successfully in the past. However, these trusted methods were once also highly innovative and groundbreaking!

There is a clash here. If you are in court, then the judge, the people involved, the public prosecutor, and the legal defense all have a very simple question. Did that person fire the gun? Did the suspect produce these cocaine samples? However, forensic scientists and experts need to take scientific uncertainty into account. When the expert involved tries to explain this uncertainty, everybody starts to think, "You are the expert. Why are you telling this difficult story? The question was very straightforward; just say yes or no based on your expertise and experience".This is why forensic scientists and experts must also be great communicators, being able and willing to explain difficult scientific aspects in a simple yet convincing manner.

Collaboration is essential to developing such a methodology and successfully introducing it in forensic practice. For a lot of the research I do, I arrange a 'triangular collaboration' involving academia, commercial companies, and users. I need forensic practice because they need to tell me how an investigation is conducted and the problems and challenges they face. They can also supply me with samples from actual cases rather than artificially created samples. These are really valuable samples on which to test and develop the methodology.

At the same time, we need companies and technology to realize our ideas and develop viable and robust instrumentation. A very powerful method may exist, but the research group involved is often not capable of taking the next step and developing a product that could really make a difference. Many innovations fail because of this. Involving a company that is able to develop, introduce, and maintain a product is the magic ingredient that you need to be successful.

Basic instruction would suffice. It is very simple. You have the platform. You take the PowderPuck, a small portable benchtop, and put it on the table. You take a glass vial, put in 0.5 to 1 gram of a powder sample, put it on the instrument, and press scan. That is it. I think a 5-year-old child could get it right.

I have attended several of the National Institute of Justice (NIJ) sessions here. You hear a lot about forensic science and the advancements in several areas, but there is clearly a lot of interest in portable technology and bringing that analytical technology out of the lab and into the field.

When you go out here on the exhibition floor, there is an interesting transition ongoing in terms of not just technology being presented but also computing possibilities. This allows you to create products that transfer data wirelessly, get results on your mobile phone, and connect to central servers where powerful computers carry out complex data analyses and send results back to the user. I think that we will see many more of these types of developments opening up a whole range of possibilities.

Years ago, you would go into the field with a Raman instrument, and everything would have to take place on that single instrument. But this limitation does not exist anymore. Now, you can take the measurements, send the data to a central location, and share it with other users.

Experts can also examine the data from a distance and perform a quality check on the data in seconds. To the user, this seems almost instantaneous as results appear on the smartphone or tablet. But in the mean time a lot is actually happening 'under the hood'. I think that these data science developments will revolutionize analytical chemistry.

The presentations and meetings with scientists are nice, but I think what makes Pittcon very special is the exhibition. It is massive! There is no equivalent to that in Europe or the Netherlands, and I find that very inspiring.

There is all this energy and activity, particularly when it comes to analytical chemistry. It is never only the science, right? There must be instrumental and technological developments to back it up and really make a difference, and that is what you see on the expo floor.

The first time I attended Pittcon was in 2014 in Chicago, and again in 2017. When you go out on the expo floor for the first time, it is mind-blowing. I had never seen anything like that before, even having been an analytical chemist for many years. You get this feeling of really getting into it, talking to people, touching instrumentation, and hearing about great ideas.

It is inspirational to see other types of applications that can trigger questions like, "Oh, what would the forensic angle be here? Could it be useful? Could I use this to solve a crime?" Then you start talking to people. Some of the projects that I am involved with have actually emerged from these types of discussions.

Arian van Asten is a full-time professor in forensic analytical chemistry and on-scene chemical analysis at the van t Hoff Institute for Molecular Sciences, Faculty of Science, University of Amsterdam. His research interests include the chemical profiling of explosives and drugs, the analysis of (bio)markers of CWA (Chemical Warfare Agent) exposure, rapid chemical identification at the crime scene with portable instruments
, the forensic use of comprehensive 2D chromatography, chemical imaging of forensic traces, and the use of data science and A.I. to generate forensic chemical intelligence from large volume forensic case data. In addition, he is the director of the Master Forensic Science at the Institute for Interdisciplinary Studies of the University of Amsterdam, the only 2-year full-time MSc program in forensic science in the Netherlands. Together with prof dr Maurice Aalders he leads the Co van Ledden Hulsebosch Center (CLHC), a national forensic network organization named after the first Dutch forensic science pioneer. Prior to his transfer to the University of Amsterdam in 2018, he worked for over 12 years at the Netherlands Forensic Institute as a member of the management team, department head, manager of R&D programs and forensic coordinator of complex, international cases, including bomb attacks and airplane crashes. He has (co)authored over 80 peer-reviewed scientific publications on (forensic) analytical chemistry and is the author of the academic course book Chemical Analysis for Forensic Evidence that was published at the end of 2022.

This information has been sourced, reviewed and adapted from materials provided by Pittcon.

For more information on this source, please visit Pittcon.

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Chemical Clues: Real-time Forensic Analysis of Drugs and Explosives - AZoM

A new compound that binds to a part of the -opioid receptor (OR) could be a useful tool in preventing deaths from opioid overdose. The molecule works in conjunction with naloxone, boosting its effectiveness seven-fold.

Naloxone is an effective treatment for opioid overdose. However, larger and repeated doses are needed in response to overdoses from more potent synthetic opioids such as fentanyl.

In a search for a potent alternative to naloxone, researchers screened a large DNA-encoded chemical library and identified a potential candidate that was highly selective for the -opioid receptor. This new compound codename 368 is a negative allosteric modulator that binds to the OR but at a different site to opioids. The researchers explained that, until now, selective potent negative allosteric modulators for the OR had remained elusive.

The researchers found that when 368 was bound to the OR, it enhanced the binding affinity of naloxone, boosting its potency by over seven-fold. Observations made using cryo-electron microscopy showed that 368 worked cooperatively with naloxone to potently block opioid agonist signalling.

In vivo mouse models revealed that the addition of 368 meant that lower doses of naloxone could be used to effectively inhibit the effects of morphine and fentanyl, while minimising withdrawal symptoms.

Further screening of other negative allosteric modulators could help uncover their mechanism of action and improve the effectiveness of these compounds, the researchers write.

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Companion compound for naloxone could boost opioid reversal effects, save lives - Chemistry World

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Establishing the origin of Marcus-inverted-region behaviour in the excited-state dynamics of cobalt(III) polypyridyl ... - Nature.com

Chemists at the University of Konstanz describe how they have made a very unusual reaction possible.

An old dream of mankind is to combine the best of two worlds: to bring together the advantages of two opposing things without having to accept their disadvantages. This old dream is also being pursued in chemistry: how good would it be to combine the properties of organic and inorganic substances?

Organic substances stand for high functional diversity, while inorganic substances are very stable. The fact that chemists want to bring them together in the form of hybrid materials is nothing new. The only problem is that organic and inorganic substances require very different reaction conditions. You can't just throw them into a pot and stir them twice. Or can you? Prof. Dr. Miriam Unterlass' research group at the University of Konstanz has developed a process that can do just that: a "one-pot synthesis", as the chemists call the process, or rather a "one-pot synthesis".

"One-pot synthesis" means exactly what the name suggests: The very different reagents are not treated separately, but are all brought together in a common vessel. It is very important that the reactions of the different substance classes take place at the same time and synergistically. However, for this to work at all, the right balance must be found between the very different reaction conditions. This is very tricky and requires a lot of laboratory work, but as the chemists in Constance show, it can be very easy with the "right recipe".

"The beauty of our approach lies in its simplicity," emphasizes Frank Sailer, who was instrumental in developing the one-pot synthesis in his doctoral thesis. "Just like a stew, you have to find the right cooking point so that the lentils have not yet disintegrated, but the potatoes are already cooked through." Applied to chemical reactions, this means You need the right ratio of pressure, temperature and time. And, of course, the right ingredients.

"We don't need any toxic catalysts or solvents," says Sailer, citing the advantages of the process - it is therefore sustainable and environmentally friendly. The only solvent used is pure isopropanol (the main component of disinfectants), which is harmless and available in large quantities. The main ingredients of the new material class are special dye molecules, so-called pigments, and layered titanium dioxide.

If it is so simple, why wasn't this reaction process discovered long ago? "Because the idea is very unusual. The organic components are not normally synthesized under such conditions," explains Sailer. Finding such reaction pathways is a declared goal of Miriam Unterlass' working group: she is investigating how chemical synthesis processes can be optimized by choosing the right framework conditions and lead to better, more sustainable results. "We produce better materials in a faster and more environmentally friendly way," explains Miriam Unterlass.

So is it the best of both worlds that has come out of one-pot synthesis? Strictly speaking, it is much more than that. "We don't just want a sum of the properties, but a synergetic interaction," explains Frank Sailer, "new properties that the two starting materials don't have." The new class of material that Sailer and his colleagues have created is virtually predestined for batteries due to its layered structure. The name of the new material class: Pigments@TiO2.

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Chemistry by type of stew - Can it be so easy to combine very different substances in a "one-pot synthesis" to create a ... - Chemie.de

That trust definitely showed up on screen and off resulting in viral chemistry. So who would Nyongo want to work with next? When we asked her our signature Unbothered question about what the actress needs right now (in our opinion Black womens needs arent prioritized enough. Period), she had a quick response: What do I need? I need to work on a project that is funny. I need to work on a light and funny project. You can say a lot about Nyong'o's filmography but "light" probably isn't the first word that comes to mind. After winning an Oscar for 12 Years A Slave, Nyong'o's biggest films have been Us, the Black Panther and Star Wars franchises, and spy thriller The 355. None of those are going to leave you in stiches, but as Nyong'o proved in our interview and throughout the Quiet Place press tour, she's got comedy chops. She even has some dream co-stars in mind: "Yahya Abdul-Mateen II or Donald Glover," she says after some thought.

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Lupita Nyong'o On Cats & Chemistry With Joseph Quinn - Refinery29

By Antonis Stroggylakis/info@eurohoops.net

There were a lot of things that Greece guard Thomas Walkup loved about the win of his team over the Dominican Republic for the Olympic Qualifiers. What particularly pleased him was the level of basketball that he and his teammates delivered in a sold-out Peace and Friendship arena.

Its not just about the winning, Walkup said. Its about the quality of basketball for us. Not just tonight but in general. From the very first day it was about the quality of basketball. And tonight I think we had a pretty good quality of basketball.

Thats an understatement. Greece produced 109 points on 27 assists for just eight turnovers a number that gets even more impressive considering how fast-paced the game was at times. Vassilis Spanoulis players executed with the precision of 36 out of 57 from the field and their offensive prowess and fluidity generated plenty of beautiful plays and highlights.

Everybody is unselfish, everybody is willing to pass, everybodys passing the ball when they should pass the ball, Walkup commented. Its really just fun basketball to be a part of because you see how the ball is moving and how everybodys playing in rhythm.

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Walkup himself successfully played a perhaps unlikely part of a scorer rather than his usual role of facilitator. He finished with 17 points on 6 out of 9 shots, including 3-6 triples and a couple of key buckets when the Dominican Republic was trying to come back in the game during the third period.

Strangely enough, he didnt register any assists. There was no need to.

Im comfortable wherever I need to be used, Walkup stated. Whats great about this team is that everybody is playing for the guy next to him. Thats what makes it flawless.

Considering that training camp began just two weeks ago, Greece is displaying some enviable chemistry. The kind of which you find in groups that have been together for a long time.

The players communicate with each other on the floor very quickly and quite smoothly, finding each other easily, distributing the ball around with speed and being at the right spot at the right moment for their teammates to find them.

Walkup doesnt believe that this is about any tactic or strategy and attributes this to the mentality that he and the rest of the guys carry on the court.

I think its the character of the team, Walkup mentioned. Everybody is unselfish. Everybody wants the guy beside him to do just as well as themselves. It makes it easy to play for someone else. To play for the next pass, the extra pass. It also helps when you have Giannis who can create everything.

Speaking of Giannis Antetokounmpo, the Milwaukee Bucks superstar had a literally unstoppable performance of 32 points on 11 out of 11 shots. The only way that the Dominican Republic could hope to put any brakes on him was by fouling often rather hard and sending him to the line.

It was great, Walkup said on sharing the floor with Giannis for the first time in an official game. He was flying up and down the court. Hes creating something out of nothing a lot of the times. Nick [Calathes] also did a pretty good job of getting him involved too, giving him a lot of easy buckets. I dont have to tell you guys you can watch the game and see how incredible he is.

The one who has infused Greece with this kind of team ethos is none other than Spanoulis. Walkup went into detail on how the legendary player and now coach set the tone from the get go on what should the dominant mindset around the squad.

From the very first day he said that there are no clubs, no egos, none of that on this team, Walkup explained. From the start, that its about the national team. Its about Greece, representing Greece. This is so much bigger than our clubs, for ourselves, than our families our friends and everything that you typically play for as an individual. Youre playing for something much-much bigger. I think thats where this comes in.

While often the main ball handler with Olympiacos Piraeus, Walkup finds himself adjusting to a different situation on the Greek national team, especially when he shares the floor with star playmaker Nick Calathes.

How does he feel about being the off-the-ball guy for a change?

I love it, Walkup said, rather enthusiastically. Of course there are still times when I do play on the ball. But I think that Nick and guy can help each other and take pressure off each other. Its tiring to play defense, bringing the ball up, create offense. I think we play off each other pretty well.

Continued here:
Greece's Thomas Walkup reveals key to chemistry, praises team unselfishness and Giannis - Eurohoops